Overall, I liked it. Yes, they made changes, and this was inevitable. The major change was that it wasn't thru-sung. This lead to some lyric changes to stop the dialogue from rhyming. The first couple of sentences would be the same as the sung version, with the last one changed slightly.
Bits I liked:
the backstory shown during "One Song Glory" and the passage of time shown in "Without You";
the opening number which sounded amazing with the amount of people that were singing it (I had to hold back from applauding afterwarRAB, though some in the cinema did);
the new bit with Maureen and Joanne (worked well, and gave one of the funniest lines in the movie);
seeing the original cast (all but two of them);
the staging of "The Tango Maureen".
"Santa Fe"
Bits I didn't like:
some of my favourite bits were cut - the christmas carolers (infact the whole section leading up to Maureen's entrance at the end of Act 1) for example. That is the only major bit, other cuts were just melodies which I really liked which were turned into spoken dialogue.
Changes from the stage version (other than already mentioned):
Joanne wasn't on the phone to Maureen in "Rent" (sounded odd, because her interjections such as "Maureen I'm not a theatre person" were just instrumental);
the phone calls from the parents were reduced;
we saw the riot after Maureen's performance as it followed on directly from the song;
Joanne was present throught the whole of the Life Cafe scene, and as a result there was no bit about her wanting Maureen to pack and leave her, therefore they were still together;
a new scene was inserted to allow for "Take me for what I am" which only works if Maureen and Joanne have had a big argument (Maureen agreed to commit to Joanne, and there was a big posh "Engagement Reception" to celebrate this, with all their families etc, during which they had a big argument and went into the song);
"Goodbye Love" was cut (we think - D and I were talking about this tonight and couldn't remember);
"Contact" was cut;
the scene following Angel's death was set in the cemetary, rather than at the undertakers;
Act 1 was set over 2 days (christmas eve and christmas day) rather than just the one;
Overall it was shifted back to 1989/90 (Mark starts by saying "December 24th 1989"). Much debate as to why this was done has been going on on various message boarRAB. The main problem with it was that Angel's reference to Thelma and Louise in "Today 4 U" is therefore a goof as the film wasn't made until 1991
Also prompted hubby and I to get halfprice tickets for the stage show the following day!