Have any of you noticed an appreciable difference using the switchblock? Not gonna be able to buy my SBR or suppressor for several more months, but I was trying to decide between a 10.5" Noveske or a 11.5" KAC for my first SBR setup. Honestly... it seems KAC has a lot going in favor for it, but I hear the Noveske barrels are the best and their switchblocks make Noveskes the best for suppressed setups. Help?

I don't know anything about the KAC line.

I do have a 16 inch Noveske switchblock, in stainless.

Very, very accurate.  I don't think anyone has bad things to say about the barrel.

With regards to the switchblock feature, I ran it a while ago with a Surefire 6.8mm can.  It cycled fine on the full setting, but was undergassed on the supressed setting (16" mid length barrel, full rifle stock/buffer set up).  I have read that the switchblock was set up for a AAC can and that can produces higher backpressures than the Surefire.

I was using 55 grain reloads, which may not be loaded to as high pressures as 75 or 77 grain loads.  I need to try it out again with some hotter ammo.

It also has the Off setting, where no gas is bled back, so there would not be any action noise either.  Now that setting is very quiet, though you have turned your semi into a bolt action.

Is the SB feature nice?  Yes.  I think it's handy to be able to turn off the gas system for really quiet shots, and the reduced gas bleedback will help will some loads/can/rifle set ups.  I would think the full rilfe buffer system needs a bit more gas to cycle than a collapseible stock buffer, so it may come in handy then.

Is it worth the 150 bucks more than a regular Noveke?  Depends how much 150 is to you.  For me, compared to the can, scope, and the rest of the rifle, it was small change, so I went with that.

I'm very pleased with the Noveske SB in summary.