Got my Boxbomber today. A decent little pair.

Their cassette modes aren't the most realistic... A bit gappy, and neither side is perfectly flat. (Usually nice if at least one side is flat, and can pass as an actual cassette.) At least they both have tape detail in the center of one side, although it is less obvious on Birdbomber.
Also, after the amazement of the Masterpiece cassettes, it is a shame they don't have integrated weapons... But I suppose Frenzy and Rumble don't either, so I'll forgive them that.
Speaking of weapons, it was a bitch to get Birdbomber's guns onto his bird mode. I understood how they were supposed to go in, but they took a lot of force to get in the first time. I was worried about breaking something! Once they did go in, however, it is easier to repeat the process.

The combined mode is pretty neat, and very poseable. I was surprised, given that he technically has twice as much to him then Frenzy or Rumble, that he's only about a head taller then them.

Overall, though, quite a nice pair, who looks good with the other cassettes. I am happy with this purchase.