I like saws that are able to change cut depth - we use ours so often for the unusual cuts, that if we couldn't change the cut depth (adjust blade height), the saw wouldn't be nearly as functional as it is. And I know some saw companies don't have that as a feature.
What else... um, a Honda engine. Light weight (the Clipper tub saw we have is just a beast to move around). A folding tray or even better, a cart option (the Clipper used 4 individual legs - made it a beast to set up, too - that's why that saw stays at the shop all year...). Belt drive.
We use the Americutter 20. The blade is fixed so it can't be adjusted. But it is big enough to cut wall blocks if necessary. The best part though is we won it in a drawing so it was free. Best investment I ever made.
We definitely like the saws with the saws with the pivoting cutting head. Seems like there are only a few options that match our criteria - EDCO, Husqvarna, and MK, and each of those use the same engine and blade size (see attached summary). We're leaning towards the Husky just because it's what we've been renting for the past 2 years with no complaints, except for the weight...
My little summary table lists the best price I could find online. I emailed the local sales-rep to see if he can provide a better quote. I'll update that table, if needed, when I hear back from him.