If I played as hardcore and constantly as I did with Diamond and had a full 36 hours and acted like a game character-- *shot*...
RBY: At least to the 7th or 8th gym
GCS: At least to the Elite Four (beaten or not, I'm not sure)
On the other hand, as soon as I hit the E4, I tend to have to take forever to properly level up to beat them-- I'm usually underleved with the gyms and barely beat those, let alone going up against the elites.... ^^;
Possible # of level 80 and 100:
Lv80: 0
Lv100: 0
Teams:
RBY- Gengar, Dragonair, Jolteon, Venusaur, Charizard, & Alakazam (based off my IRL color teams)
GCS- Typhlosion, Umbreon, Dragonair, Scyther, Haunter, & Suicune (Except Umbreon and Suicune, this is based off my IRL metal teams)
Pokedex completion: 10-20%? I tend to deal with completing the Pokedex in my games AFTER I've beaten the E4; I'll catch the occasional Pokemon that runs across my path that I want (and evolve the ones I want to evolve, thus getting more entries), but I'm not a keen catcher prior to the E4's defeat.
Now, if you told me to play BOTH OF THEM... Ehehe, I'd probably keep switching back and forth and only get to the 4th or 5th gym on either one. No level 80s, or 100s, and definately no completed Pokedex.