Has anyone done any overclocking for your DAW computer?

Overclocking is as 1990s the Macarena and Mambo #5.
 
Computers are fast enough these days that overclocking is unnecessary. Even gamers (who pioneered OC'ing) don't ereally do it anymore. Do the upgrade. You will have to upgrade anyway.
 
If you use your computer for CPU-intensive activity (video editing, DAW, gaming), you should have started with an i7 in the first place.

I also run an I5 750, and do often overclock to give a bit of a jolt to some programs, however, Sonar does not seem to benefit at all in regards to how many or how well synths, plug-ins or playback/recording actually works.
Overclocking you CPU will basically add a slight amount of speed to opening/closing of Sonar and said synths and plug-ins, but once the program is up and running you will not see much, if any at all, benefit by upping your clock.
This particular CPU is one of the most stable, well made pieces of silicon that Intel made and will run Sonar just fine, stock standard.
There is plenty of life left in an I5 750, if you want to upgrade you will see some improvements if you choose Ivy Bridge or later, but realistically you would be better served, at least as far as Sonar is concerned, by making sure you memory requirements and audio hardware are taken care of first.

I have got an intel - 6 Core i7 overclocked 4.5GHz …works great!

I have an i7 3770k on an ASUS Sabretooth MB that is so easy to run at 4.2 GHz (rather than 3.5) it seemed dumb not to do it. As a quarter of the available space in the case is taken up by the cpu cooler I have no issues with heat .

Grum.

Intel always more reliable as software gets tested on it more, that is all :)

Cheers
 
Alex

I have the AMD 8350 and I love it. Rock solid, no issues. 

I overclock my Phenom II 965 and I have no issues.  However I'm sure Sonar does not benefit in any real way from my 0.4GHz overclock.  If you're running out of CPU horsepower with the amount of plugins you have, in my opinion, no amount of overclocking for your CPU will help, realistically.  You might get one or two more plugins working but you run the risk of instability.  In my opinion, if your CPU can't handle what you're throwing at it, then you should freeze tracks as suggested or maybe consider a complete system upgrade. 
 
I have no stability issues with my CPU overclocked, but its overclocked so I can play games on my computer.  There are a number of tricks as outlined above to increase your computers ability to handle what your doing with Sonar.  I'd try those first.
 
I upgraded to an FX-6350 and I had no change in Sonar.  That's because what I do in Sonar doesn't stress it at all.  When I upgrade again I'll buy the fastest CPU I can get for about $200 - whatever that may be.  Sonar for me works with my 2008-era AMD CPU and I have no plans on stressing Sonar beyond that.  I upgrade for games.  I play games on my Sonar machine because I use Sonar in cycles for personal music - I don't professionally "produce" anything.  If I was to be more of a professional music producer I would go Mac or a separate DAW computer that I don't overclock.
 
As I'm sure you're aware, you cannot "upgrade" from an AMD to an Intel without changing the motherboard.  You need to figure that into your cost.  I considered upgrading from my Phenom to an Intel but I'd have to get a new CPU (obviously) plus a new motherboard with it's associated costs.  Instead I spent $139 on a new CPU and I got a tangible benefit in my games. 
 
As far as AMD vs. Intel, it's 6 of one, half dozen of another.  I've always used AMD.  If I wanted the ABSOLUTELY FASTEST COMPUTER at any cost, Intel is the only way to go.  Period.  However, I have never built a computer with cost being irrelevant.  So that is why I choose AMD.  If you are going to produce professional music and must have the fastest computer possible, and Intel I7 is probably your best bet. 
 
For me, I just compare an AMD Fx 8 series ($150) CPU upgrade to an Intel I7 upgrade ($300 CPU plus motherboard) - it's no question the AMD CPU is cheaper.  But it's clear in all computer literature, that the Intel series CPUs are faster in almost all cases.  So that is your decision to make.
 
You have to figure if an Intel CPU upgrade will even work on your motherboard - if not you'll have to upgrade the motherboard (and possibly the RAM) as well.  In my case I bought a new CPU.  In your case that might not be such an easy task.