Flew out of T2 last week. General impressions:
1) Check in was nice and spacious -- similar to Delhi T3 and way better than the old terminal
2) Security -- before immigration versus after in OT. Signage sucked and lines were pretty long
3) Immigration -- signage also bad here. But went reasonably quickly
4) Post security -- decent amount of F&B as well as shopping
5) Lounge -- one main lounge versus the individual lounges previously -- food was an upgrade from the Lufthansa lounge. lots of space also which is a big plus from LH
5) Gates -- decent walk from the lounge -- similar again to Delhi T3. also limited options near the gate for F&B, at least near the gate United uses.
6) Additional security -- you have to go through another round of screening for the US flights. the UA gate didn't have a lot of space so the boarding process took forever.

Will miss the old terminal -- having flown from there at least 50 times in the past 4 years, had gotten used to all of its issues.