Giant robots doing somersaults or riding jet sky surfboards whilst waving lightsabres or giant scythes have always seemed a bit ridiculous. Special powers or magic power-ups or combining with other robots *cough* Godannar *cough* - no way!
MS 08th team was probably the best at giving a 'gritty' feel. The earlier ones are also good - MS IGLOO recently has brought back the old Universal Century Zakus vs Gundams with nicer animation:
While I liked the 'combined arms' feel, I think gundams really belong in SPACE. Here is why:
-Ability to maneuver in any direction (in fact I think the RG-Ball is a very logical shape) and wide shooting arc would give an advantage over atmospheric-shaped space fighters
-Can board enemy vessels or space stations/habitats; or even clamp to the deck and act as an extra gun platform
-Can be used on the ground as a support unit as well; dropped in from orbit
For ground combat only, the superior off-road mobility, jump jets, and ability to interchange weapons is, I doubt, worth the extra complexity, size and weight compared to an advanced MBT.*
*Yes, Veritech Valkyries from Macross, with their atmospheric flight ability, probably are more all-rounders than gundams but transforming robots, I feel, fall in the 'magic robot category.'