The G3 runs cheap cleans well and never gets stuck on floor to wall transfers, but it doesn't make it to the shallow end very often.
T5 is a tiny bit larger more aggressive per watt, but can get stuck a bit easier on low power. It gets to the shallow end a lot.
Creepy Kauleys aren't bad but get hung up more in my pool than the zodiac brands do.
Of the wheeled type I like the poovergnugen.
For tracked units I like the zodiac MX8 and 5
The MX 5 & 8 actually scrub the pool floor actively with the brush kits.