hm...good question. I'm only recently been looking into the group things but, so far the things I look for in a group are:
1. Organization in the submission folders etc. It's nice being able to look at folders and get a clear idea of what the group is looking for and if my art will fit in. 2. Activity! I don't care if its contests or journals, but I love seeing people who share an interest talking to one another. 3. Community! Something that's hard to actually control, but its really fun submitting to a group and getting some nice feedback.
The other thing I keep an eye on is how the group advertises itself to get new members. It's not really a big deal, but an ad can make or break a group! I hope this helps you out.
Yep, that's why I check the content C: If it's something like rules or something, then I wouldn't mind it if it was an older journal. If it was a contest from months ago, I'd probably be hesistant about joining the group ^^