I have ProTools LE, not TDM or HD, so my experience with the wider world of PT plugins is indeed limited. I've heard them on other systems, but don't have them here to closely audition.
Some of the few plugins I like are
the Sonalksis SV-315 compressor, which I just bought, and all the Elemental Audio plugins. Good stuff.
I'm a little tough on plugins partly because I do a torture test on them to evaluate their sound. There are some acoustic piano tracks I recorded a while back that are pristine. recorded on a 9 foot Hamburg Steinway, with a Grace 201 preamp into vintage AKG C12's, directly to disk. I know the recording very well. So any time I audition a plugin I use it on these very exposed tracks that have a wide dynamic range, and breath a lot musically. Most plugins leave a signature mark of some sort, kind of a "processing" sound I call it. They do something undesirable. It is a tough test, I'll admit. On differnet kinds of tracks or a full mix the plugin might pass, but I really want to hear into the sound of it.
That said, I have not heard every plugin out there, or even the majority of them probably. The Sonalksis and Elemental Audio plugins are the first I'd heard (for AU/VST/MAS) that I feel comfortable using.
Also, I tend to put reverb/compression/eq plugs in a different category than delay, filters, modulation, and all the other wilder stuff out there. I think the standards have to be higher when it comes to reverb, compression, and eq, as the results from poor plugins in those categories is more obvious.
This is just a matter of me going with what my ears are telling me. I'm sure for others, doing different kinds of music, plugins will work fine.