I've been running 2.2.4 on my Verizon Pre 2 for a day now. I don't have a touchpad, so I'm mainly checking everything else. I built from the test-verizon-pre2-2.2.4 script current in the git repository as of about 24 hours ago. This meta-doctor DID NOT wipe my USB drive area, which I was quite pleased with. Stuff that works:
Enyo (HP Maps, at least)
Seems like everything I can think of to check works the same as before, with the addition of the features listed as new for 2.2.4. I do get the timestamps in Messaging, and it does seem like my Google Calendars sync better, although there are still quirks. And a couple patches I had installed before are not available yet. But that's about it.
I'm pretty happy with this, as far as stability and functionality goes. Mark that down as one more success for that script.
[Update] I also no longer have a YouTube app. I just get sent to the website. I have not tried viewing a YouTube video yet, but Flash on other sites works as well as before (2.1.0). And for me, the only larger fonts occur on web pages. My notification text and icons are the same as before. Some of the large text in web pages is actually nice, other times it makes the page layout a bit odd. For example, on the Google Calendar mobile page the times for events are large, but the event title is normal sized. That doesn't look so good to me. Also, in Google searches, the result links are large, and the web clip and URL text is normal. I actually like the look of that.