Hi Bob,
The RTAS version works just fine on my system (MacPro 2.66 quad, 3Gb RAM, 3xSATA HD: one for system, one for PT audio and one for VI samples) but the main difference I can see is that I'm still using PT7.3. I can easily load 12-16 VI instances in a session with a number of audio tracks and in a VI-only session I got up to around 20 (a couple more using VE) before things even started to get sluggish. It's not a wrapper, as far as I understand, the "shell" (i.e. the VSL server) is the same for the Audio Units version, it's just the way they've implemented VI on the Mac.
Given the thing about "samples not found" I'd suggest you run the Directory Manager utility and rescan for your samples. You don't say where you're storing them. The best way (is to have a separate internal SATA HD for your VI samples. I assume you've already repaired permissions and obvious things like that.
I'd certainly start by running the Directory Manager and making sure all your samples are recognised. It could be as simple as that (though no promises, obviously!)
Feel free to post any more info (or e-mail me).
Regards
Nick
Mac Mini M2 16Gb RAM 500Gb int. SSD 2Tb ext. SSD Pro Tools/Mixbus An awful lot of VI, Synchron-ised and Synchron libraries, amongst others. VSL user since 2003.