MG-'93, while not the most striking of the various Meha-G's Toho created, is still quite nice. The original, one has to remember, was built as a weapon of mass destruction, and with its sharp angular edges. Creates quite an imposing figure. The UNGCC model, is a product of the nineties. Its more utilitarian design looks like the majority of the vehicles of the time, as opposed to the muscle car the original was. But MG-'93 does get the job done. It gave the Big-G quite a fight in its first meeting, and damn near did the King of the Monsters in the climatic confrontation. Not mention laid out Rodan quite nicely. It also took the Super-X II's numero uno weapon, the Fire Mirror, to the next level with the Plasma Grenade. And used it to deal out some major punishment. Hell, the MG-'93, when in combat, although used the beams a lot, rained HELL on the Big-G. Especially, when hooked up to Garuda to form Super-Mechagodzilla.
One of the bones of contention with the fans about the UN-MechaG is it being prone to mechanical difficulties. I actually liked this, and made the mecha more realistic with it breaking down at crucial moments. Its MegaBuster unable to fire due to overheating during combat. Likewise its lack of physical combat abilities, it was unable to fight off Rodan to prevent the winged menace from pecking one of its eyes to nonfunctioning status. The original in its initial outing suffered from a bit of a breakdown after its first battle with the Big-G. Kiryu, with its mood swings due to it's DNA computers, finite power supply, and getting damaged in combat. Although, as I remember, Godzilla wasn't giving Kiryu much room to fight back in their second encounter.
While some here may be a bit put out that it was a little far fetched that UN-Mechagodzilla was developed through the reverse engineering of tech salvaged from the future tech from Mecha-King Ghidorah. It should be noted that it was mentioned by Colonel Gondo in Godzilla Vs. Biollante that Godzilla Countermeasures Center was doing some extensive research into robotics. So with the introduction of MKG's tech to the research being done in the field, and it probably gave the robotics section quite a boost in their research.