I use Beejive , and believe it is worth every penny , it truly is like using an IM client on your desktop , its instant and so is the push , the set up and layout is perfect , and to have every chat client put into one and pushing its amazing.... Now i cant speak for IM+ but i can say Beejive is worth 10
i was actually thinking the same thing yesterday when i purchased im+. i do think that push is going to become a way to distinguish the "lite" version from the full verison. i also agree that its kinda messed up on the devleopers side to do this. i got the palringo update last night, and cant remember if it was palringo lite or not before the upgrade. i didnt think it was listed as lite.
i ended up getting im + and have been very pleased so far. i was also wondering about the whole leaving it on for 3 days and the battery life, so i lowered it to one day just to see how it does. i cant see how that would matter, but i'm kinda weird and ocd that way.