Over the last three years we've tested quite a few brands of phones. Most of them were real crap, only very few were reliable. From the better ones our users preffered the Polycoms.
The Polycoms (and SNOMs) are probably the most expensive ones. Polycom has the central boot server provisioning method which saves on initial setup manpower (SNOM proobably has the same - didn't test).
Polycoms are also quite intiuitive for the user, so less support personnel... This is currently crucial to us as we are deploying them using already busy staff.
BTW, we did not tried Aastra as they are quite rare here.
Regards, __Yehavi: