I think for me what the biggest difference between the original series and 2202 is that, for all intents and purposes, the good guys "lost". The Andromeda, the entire EDF, and their crews, were lost to the Comet Empire fleet and Gatlantis, the moon was turned into a "flaming ball of fire", Earth surrendered for a time, then was blasted by Zordar's dreadnought, probably causing untold environmental damage and millions of deaths, and the Yamato is left a wreck with only 18 survivors. If not for Teresa's arrival at the end, the Yamato would have been lost as well.
And, although it's never really touched upon in subsequent movies/series, Earth never really fully recovers from the losses sustained at the Battle of Saturn in terms of ships and manpower. In 'The New Voyage' it's just the Yamato. In 'Be Forever Yamato' it's a handful of automated battleships that are quickly ambushed and wiped out. In 'The Bolar Wars' we see a light EDF cruiser and the battleships 'Prince of Wales', 'Arizona', 'Bismark' and 'Novik', all of which are lost during the course of the series, and in 'Final Yamato', the evac fleet and escorts are destroyed, leaving only nine serviceable ships to escort the Yamato in battle against the Dengil..
With 2202, I don't get that same sense of loss/defeat. Sure, hundreds, if not thousands of ships are lost; but, most, if not all, of the EDF fleet is fully automated by the time we get past the Battle of Saturn; and; thanks to the 'Time Vault', most of those losses are made up for, even after Zordar and Gatlantis are defeated.
Also, except for a portion of the moon being blown off, Earth was untouched by Zordar.
As for those who died in the final assault on Gatlantis, I was 'Meh'. Maybe it's because I watched the original series when it first aired, and subsequently found out about who died thanks to the Perfect Albums is bought a few years later; so, when they died in 2202 it didn't have the same impact. Even the Yamato, with her wave-motion shields, visually appeared to escape relatively unscathed.
The only good thing about the final episodes was the arrival of the Gamilus fleet to help the Yamato in its final assault on Gatlantis; something that the original series should have done.