First the good:
A lot of sounds - and a lot of them useful for all sorts of settings. Even with 2 DVD drives, it took quite a while to load all the discs. Some of the arpeggiations were really fun to play around with and I could see them being very useful in the right musical environment. Some of the legato tricks (like slurring and gliding between notes when the previous key is held) provide a realistic performance. These are most interesting (at first listen) on the acoustic bass and woodwinds. For my purposes, I'd probably get use out of maybe 40-50% of the sounds over the lifetime of the app (or the user).
MachFive-1 and -2 presets loaded right in as did the UVI and Kontakt presets. The newer version of Garritan (Aria Player) did not and neither did the Miroslav Phil CE presets. Not really a big loss. My M5 1 & 2 libraries are quite extensive and I've customized a lot of sounds for design. It is very comforting to know these just drop in and I don't have to do anything. It's also nice to know there are fantastic tools to make them even better now. Not unexpectedly, none of the Korg legacy presets would load either. Again, no big loss as they are simple enough to load from their native apps.
...and the bad:
Not so bad really. With DP hosting it, DP will remember the last loaded M5 patch (as long as you save the project but there is no warning that you changed a patch so if you don't save and change a patch the last saved project patch will appear). If you change or tweak the M5 patch and quit or close the project, there is no warning that the changes will be lost - and they will be lost. Perhaps there is a preference for that - I couldn't find it. Even something as simple as changing the overall volume or pan setting from within M5-3 will be forgotten, at least by the M5 plug-in.
In stand alone that is not the case. Make a change and the standalone version will warn you to save or discard the changes. I can't imagine that is a useful nor intended implementation. You do have the option to save changes to a new user preset, but not everyone remembers to do that and if you're like me, you instinctively hit CMD-s, CMD-q, grab your coffee and rush out the door. It would be nice if M5-3 would at least warn you that you have unsaved changes.
Interestingly, in Plogue Bidule, that app does remember changes to M5-3. It doesn't ask you to save them, but PB saves them. You'd think DP would as well, but no!
The factory patches I liked, I liked very much - some of the others... not so much. I was hoping for a better orchestral library and while it's not terrible, well... I guess I'm just spoiled. I'll just spring for the LA Scoring Strings and shut my face on that one. Then again, I have not tweaked ANYTHING yet so it may be that the presets can be massaged into a more useful sounds. There are certainly a lot of samples and the potential to adjust them to one's taste is clearly there, so I may be overly harsh in this regard. Out of the box, I'd probably not use too many of the pitched orchestral sounds on a regular basis. Percussion is excellent and the shakuhachi #2 is really a delight.
...now the Ugly:
Not Lady Gaga butt ugly, but bad enough. More than a few patches could not find their samples. I probably ran into maybe 4 or 5 that would not load and returned errors. Also, some of the presets were just a waste of space, IMO. Really useless for any purpose I could imagine. I already had the ExtremeFX package so I didn't load that from the MOTU DVDs. I did load the UVI version and it went right in. No sense in duplicating it and going thru the licensing thing again.
So once again, as they used to say on American Bandstand - 'I'll give it a 90.' I have NO REGRETS in purchasing the upgrade and can't wait to play with the totally awesome (in the truest sense of the word) processing. The online videos James mentioned only scratch the surface, but are great to get a sense of the power and interface. M5-3 is not completely the 'universal' end all sampler, but it's no dog and considering that I'd only use half the sounds, that is still a damn lot o' sounds.
Now if MOTU doesn't wait 2 or 3 years to update the plug in so it works like the standalone when it comes to reminding the user about unsaved changes (and not loose track of even a few samples) that would be a very good thing.
OK... I'm done.
Oh yeah, I still need to...

About 250 pages and at first glance, I really need to...

ps- Save and lost samples reported to MOTU as a Techlink.