My practice kit came with UT heads. I've been using them for two years. In my experience they hold up well. They sound like lots of recordings from the 1960's. I plan to replace them but they are OK, so there is no rush.
That's my opinion too. Throw some control rings on them and they can sound pretty decent.
I do usually change out heads right away, but I wouldn't say it's necessary for everyone. Especially those on a tight budget.