The only one would be worth buying over the Misi is the PWR with the built in oil cooler.

Misimoto also has an incredible warranty, replacing the radiator for free if you bend it in an accident.

 

"Worth" is a personal value. If Mugen shit is not worth it to you, cool. I've bought Mugen, some new, most used and it's all been well made and worked fine. A Rolex doesn't tell time better than a Casio but I don't think that's the point, same thing here IMO.