I can think of a lot of goods reasons to upgrade to SPLAT without even considering CPU load balancing, however you may be too late.
But you can still get the tools which are actually just Audio Plugins and instruments that makes SPLAT superior to Pro from 3rd party vendors even if Gibson won't offer them any longer.
Ever check out the plugin suite that comes with any Focusrite Scarlett audio interface? You could save money on the plugins and instruments by purchasing a Scarlett 2i2 and throwing the interface in the garbage, LoL, but that would be an insane thing to do, of course. Focusrite also has a free plugin collective program that offers really high quality plugins from time to time like a full licensed version of XLN Addictive Drums 2 (same as came with SPLAT) Addictive Keys which is equal to or maybe even better then SPLAT's Real Pianos plugin, depending on some ENORMOUSLY varying opinions ranging from extremely biased to none bias.
But seriously though, the Drawmer S 73 dynamics mastering compressor(s) plugin that comes bundled with the SoftTubes package is worth the price of the 2i2 all by itself. And I'm just naming a few.
But there sure are some great and useful Cakewalk audio plugins and instruments that would almost be a sin to lose that came bundled with SPLAT that actually gave it super value packed, even though it cost(ed) $300 more, now it will most likely cost 2x that to catch up thru 3rd party vendors that Cakewalk USED to license from or vendors of equal quality.
Vendors like iZotope, Waves, and Eventide can get to be pretty pricy collecting plugins even with their super sales offers.
Have you tried looking on the Tascam website? I would think, but don't actually know that they would offer an upgrade there for their new line of Tascam recording systems which uses SONAR PRO as the central DAW software. It would seem to make sense for Tascam to at least sell Plugins like the Adaptive Limiter and or Rapture Pro separately somewhere.
It seems to me that SONAR has been incorporated into the Tascam recording suites lineup where they now sell it as part as a system OS for their carefully designed preconfigured and packaged recording system completely bundled with a computer, comprehensive set of high quality basic audio FX and vsti instruments suites, audio interface, mic, and headphones "
That they tested and KNOW will work and be compatible with each other!" Comparing it to high performance a race car, I kind of look at it as a nitro burning Tascam Porta Studio with an overhead cam and open headers designed to run as flawlessly as it can with a relatively small engine get to capture and successfully record 8 -16 tracks of audio on an affordable moderately powerful Intel i5 CPU .
I've seen and know people who already have been doing that for quite some time now since SONAR X3 with i5 class systems which hold up GREAT in a project until they get burdened with "MIXING" sessions with too many automated tracks with too many plugins and synths running. Not to mention those who think nothing of using heavy hitting CPU intensive mastering plugins on tracks and or running mastering suites like iZotope Ozone in the main output buss all at the same time...
Don't get me wrong, I am a great fan of iZotope, and particularly Ozone, but only use it with Sound Forge during the finals for mastering sessions.
Anyway, I'm thinking you've missed the boat on getting a "Cakewalk" SONAR Platinum upgrade.
I believe it was Craig Anderton who said "Trying to keep up with fixes, patches, and updates is like trying to hit a moving target", and I couldn't agree more when it comes to such a wide array of users from starter, novice, on up to skilled audio/MIDI engineers, and using such a wide array of computers from decades old machines to current tech, from ultra cheap bargain box laptop computers they bought at the Wal-Mart blowout sale on up to high quality component and performance workstations.
As much as I don't like to say or even realize it, I don't blame Gibson Brands for throwing their hands in the air, shuttering the Cakewalk brand, and keeping the technology alive through Tascam.
And even if they drop the SONAR name completely and call it by another name, the technology still lives on....
And SONAR goes on to live to be "The greatest and most coveted vintage DAW the world has ever known."
Ya know, kind of like some old worn out '69 Les Paul Custom with it's paintjob peeling off, or that beat up mystical '64 Fender Deluxe amp, both of which can command ridiculously stupid sums of money to not only covet, but to keep up and running, AND none of which Gibson of Fender will ever see..
My experiences with SPLAT's CPU core load balancing didn't "seem" to have any useful effect on my 4th gen Intel i7 on the brief time SPLAT was installed on that machine.
SPLAT appeared to only use as many cores as it needed with the first core running the hottest averaging between 50%-75% with a 30 to 40 track project. If one core spiked hard enough to cause an audio engine dropout with load balancing off, the core wouldn't spike with load balancing turned on all cores ran and danced around 50%-60%, but the audio engine dropout would still occur at the same exact spot on the time line
My experiences with SPLAT's CPU core load balancing with the AMD FX 8370 turned on and off are quite different but mostly appear to be only visual with an equivalent 30 to 40 track project.
With it off the first core does the brunt of the work dancing rather quickly anywhere between 30% up to startling red zone spikes, but the other cores kick in quick enough to avoid any audio engine dropouts, though may produce a quick but passing none destructive stutter.
With core load balancing turned on the FX 8370 runs smoothly with all 8 cores dancing between 20%-30%, it rarely breeches 50% on any core but when it does it may produce a quick but passing none destructive stutter.
I can only assume the differences in percentages and performance is due to the AMD architecture of having 8 physical cores running at a much faster base clock CPU, FSB + PCIe Buss, and memory timing speeds allows for smooth operation running the Focusrite 18i20 @ lower latency @ 128 bit buffer as opposed to the slower across the board i7's 8 virtual core and buss architecture slightly higher, but not really humanly detectable latency smooth operation @ 256 bit buffers. Well, at least this human can't detect the difference between 2.7 ms and 6 ms in real-life recording latency, LoL, so these numbers mean more then nothing as does load balancing.
Believe me, there is nothing wimpy about that i7 machine, and it's powerful enough where it can rock steady and deliver excellent results without ever having to change buffer settings for mixing sessions.
But then I never have the occasion, even in very complex orchestrated compositions where I need more then 48 tracks to get my musical ideas or point across.
I'd also like to point out with the observation that weird and unpredictable things can happen to a project when you keep switching back and forth turning load balancing on and off to make quick comparisons only produces weird and unreliable results.
But truth be told, I actually don't know if load balancing has any benefits other then making the performance meters less distracting, and when the meters start to average around 30% it's a subtle reminder it's time to start freezing and saving tracks I'm committed to and no longer working on.
I leave it on because I've recorded many projects now with it on and it never produced negative results and a really, really detest seeing red warning lights coming on anywhere in the GUI during recording as much as I do on the instrument panel of my car.