Like the title says i'm thinking of a Saker ASR 762 for my 300BO which will also go be swapped onto my 5.56 SBR from time to time (the reason for this being that I already have that SBR set up with a silencerco muzzle device). Was hoping someone could give me some first hand experience feedback with this can before I pulled the trigger on it.

Is your 556 shorter than 10"? Are you going to use it on a 308 shorter than 16"?

If not, then why are you considering the Saker ASR over the Omega? Omega is significantly lighter, inches shorter, and just as quiet (quieter on 300blk apparently). 

I don't know how new you are to silencers, but my first can was 21oz, and I hate it now that I'm used to the 14oz Omega. Saker ASR is 23oz. No thanks. It is extremely durable, but if you have no specific use for the durability, go for what meets your needs with fewer downsides. 

I have a 10.3" and 7.5" upper for the 5.56 and the 300BO is 8.5" I can take a look at the Omega too. Like you are suggesting though with barrels that short the extra weight isn't going to be too much of a bother for me. I was actually thinking about the omega for some of my 308 rifles with conventional length barrels so i might end up getting both

Always get both. 

Omega is fine on 10.0" 556 and 7.0" 300blk (subs or supers). If you really want to suppress the 7.5" 556, and you're considering both, you might consider a Saker ASR 556 or 556k, since that will give you the benefits of a more robust can without being 23oz+ and 10" long but since your 30 caliber hosts are all within the capabilities of the Omega, you could also benefit from its 7" 14oz of goodness. 

Thanks man this is the kind of info I was looking for. Honestly the only reason I want to suppress the 7.5" is because it doesn't "look right" with a flash can or similar muzzle device in it's current config and without one it is simply obnoxious to shoot indoors or close to other living things.

If your going with one can the 30 cal saker would be my vote. I've run my Saker on everything including a 7.5" full auto AR15 . The thing is built like a tank but weighs as much.
Having a few other cans now I still don't regret the purchase but I might have done what was suggested above a 556 saker and an Omega .

I had a 7.5" 556 upper, but due to the fact that 1) the ballistics are unimpressive 2) I didn't feel like spending ~$1000 just to suppress just that particular upper when I already had several cans that work on all my other guns and 3) due to #1 and #2, I rarely shot it anyway other than just to burn steel ammo at the range, which I can do with a 10.3" upper just as easily and its just as fun. 

My solution was to replace the barrel with a 7.5" 300blk barrel which offers much better ballistics out of the same barrel length, meaning I can actually feel comfortable using it for something other than plinking... and I can suppress it with the cans I already have. Like I said, I have a couple other short 556 uppers that I can still use to plink, but they are long enough to suppress without dropping a grand on a Saker. 

I love the form factor of the 7.5", and I already have an 8.5" 300blk, but this way I get everything I want. I figure for the $1000+ and hassle and wait time I'd invest in a Saker, I could buy a lot of 300blk ammo, and for $80 for the AR stoner 7.5" 300blk barrel from Midway, I didn't lose very much after selling the 556 barrel. 

I have a Saker 762 (non ASR) and it is a beast. It performs beautifully on my 9.5" 300BO and on a couple other 556 rifles I have the muzzle brakes for. To be honest I shoot it more on my 556 rifles than the 300. If you want brick sh*thouse like durability go with the Saker. If you just want overall use can I would agree with the others and recommend tue Omega. I do not have an Omega, but one of my shooting buddies does and the weight difference is notable.