ASIO or WDM for SONAR Platinum and SCOPE 5.1?

Use whatever works best, doesnt matter.

The ASIO drivers suck?
 
Speaking of which did you verify you have the latest drivers?

On my Roland Studio-Capture, the ASIO drivers are better.  I can get lower latency than with the WDM drivers.

I don't get it, from your post I would have figured Scope was an obscure brand of audio interface but I see it's just software? 
http://sonic-core.net/joomla.soniccore/index.php?option=com_content&view=article&id=138%3Ascope-51-for-64-bit-version-of-windows-7&catid=36%3Afaq-scope-dsp-audio-platform&Itemid=56&lang=us
 
What audio interface are you using? 
 
And the story goes is there is no difference in audio quality between ASIO or WDM. But generally speaking audio interfaces that use ASIO drivers have better performance and latency.
Cakewalk recommends you try both and see which one works best for your set up.
Sounds like WDM is working better for you. And this might be like  Dave is saying,  I think he's being funny so don't take it wrong, A more polite answer  might be the company never wrote proper ASIO drivers for what ever audio interface your using. 

I plan on using two integrated systems. A Prostar i7 Windows 8.1 notebook with SONAR Platinum and VSTs on top of the MOTU with native ASIO. The other system is an HP XW4600 Quad Core Win 7 64 with Platinum on top of SCOPE 5.1. The two systems communicate via ADAT and MIDI.
Recording is done on either one or both depending on the project. Everything is sync'd at 48Khz over ADAT and MIDI so control surfaces work across the board and either system can be the main transport controller.  It's a bit complex but the SCOPE system is really the workhorse because of its pristine native DSP processing which no DAW can touch before crashing and stuttering, etc.  I use the SONAR notebook without overloading the CPU (which is overclocked at 3.5 Ghz with 32GB worth of RAM and dual SSDs so it's pretty max headroom) for VSTs like AVOX and Guitar Rig and Kontakt 5 etc., which consume a lot of CPU. It's pretty solid with the MOTU which I also use as a direct box and pre's.  Between the MOTU and SCOPE cards it gives me over 224 channels of which 40 are analog. The most I would use is a mix of tops 32-40 with mostly digital including MIDI.
 
Now it's back to tweaking. So far so good now that I remembered how to set the ASIO2 channels in SCOPE! Doh!

Scope is hardware/software.  The hardware is based upon early Shark cards (like what UAD uses).  I don't think they are still selling new systems but a lot of people still have them and there is new software in Europe, I think.
 
I have no idea why the Scope ASIO wouldn't find all the ins/outs.  Of course, I don't think I could find 224 ins/outs. ;-)

Well it's certainly something I never heard of and I read just about every dang music related magazine and such since the beginning of time. So thanks for something new to ponder. 
Glad you got it going that's the main thing.