Umiya sushi was a great find for AYCE sushi. It's a little outside of the strip, but definitely worth the trip out there. My partner and I walked from the Excalibur thinking it wasn't too far -- we wouldn't recommend doing this, as we walked for over an hour and had to cross the freeway.
Umiya had a great selection of items, and all of their staff are super attentive and friendly. The neat thing is that Umiya lets you do "half-orders" so that you can try a lot of different things. We didn't see any sashimi on the menu, but this was fine for us since we had poke.
Great price point for AYCE -- we really didn't feel like paying premium prices that you'd typically find I the strip. The restaurant itself is quite large, and unfortunately there wasn't a lot of people there when we went on a Tuesday night (unfortunate because it's quite a cool spot). Those that were there -- we think -- are locals, so it's nice to dine where locals dine.