Is MUT worth playing if you don't buy packs?

[Jarbeez]

I would say yes. I do not spend any money on this stuff and have a blast with it. I currently have an 85 OVR team.

You get plenty of coins from solo challenges to help build a team.
You get packs and reward players that can also be used.
There is plenty to keep you busy and challenged.

I do not play a ton of H2H, currently 6-2 H2H record, but working on the solo challenges and collections/sets, etc.

Also, for some side fun is working the AH to find extra ways to make some coins for those players you covet.

[Dang3rousPeach]

I just started doing ultimate team this year and have been enjoying it for the most part.. I havent done much head to head so im not really sure how my team stacks up (81 overall).
ive found that you can get decent players (gold low 80s) for pretty cheap on the auction house.. which imo has been better value than the pro packs turn out to be. The auction house so far has been my favorite part.
The two things I dont fully enjoy:
Having to grind out more games on rookie difficulty...
I wish I could buy the 75k coin pack... but have never had more than 15k coins... so I feel like my team will be somewhat capped when it comes to getting to the next level (I havent/wont buy packs with real cash)

[goillini03]

I like doing the challenges and I try to give myself some weekly goals. IE: finish two teams regular seasons and buy a replacement dline or buy cards needed to upgrade a Rising Star. It is kind of a nice break from seasons against the computer. Still playing a sports game but also adding multiple challenges along the way.

[Capn Cowboy]

I gotta tell ya, I started MUT last year in 25, really just dabbled in it, but, MUT is all I play now! It is pretty fun, but in all honesty, I haven't played online. I haven't spent any real $$ (yet), not really sure if I want to. My team is a SR offense and a ZD on D, I believe my team rating is somewhere around 75. I figure it's pretty safe this way. I haven't played much, but every time I do play, I play for a few days in a row.