Hasbro always seems to miss the mark when it comes to making a good set of combiners. FOC Bruticus gets pretty close to hitting it though. If it weren't for the long and skinny arm that Blastoff forms or Vortex's weird hand shape or the hollow looking torso (when viewed from the side), I think it'd be darn near perfect. I like how the hands, feet and head are all nicely tucked away in each of the figures - no spare parts have to be added to complete the final combined mode. Each of the individual figures also have great looking alt mode bot modes with a decent amount of articulation. Not perfect, but it's definitely getting there. What sort of attributes and features would your ideal combiner have?