I have Waves on several different systems here, and move one ilok between them, depending on what room or DAW I'm using. Never had a problem with tech support when I told them this, so it must be A-OK with them. In fact, it's the main advantage of iloks over system-resident licenses.
Waves are not the only game in town, but they are on the A-List for sure. Linear Phase EQs, C6 with sideband, X-Hum, L3 LL Ultra, the Renaissance stuff, and the S1 stereo tool are on so many projects, it's hard to imagine not having them.
I also like to meter the final buss through their Durrough meter. It makes it easy at a glance to get the levels high enough, but not too high, and to keep peak/average in a good range.
It wouldn't surprise me if their litigators might have been over-zealous in a case or two, but I also wouldn't be too surprised if some of those stories were not quite true as told.