thanks for all the input.
i was fully decked out at 19, leveled and loved 29.
i was fully decked out at 29, leveled and loved 39.
i was fully decked out at 39, leveled and loved 49.
i was fully decked out at 49, leveled and loved 59.
i was fully decked out at 59, leveled and loved 60 even though i wasn't geared to the max at 60.
i then leveled and loved 70 better (skipped 69).
so i am pretty confident that i will not regret leveling out.
let me use chess as an example,
10-19 bracket is like pawn endings, 20-29 is like knight/bishop endings, 30-39 is like bishop and knight endings, 40-49 is like rook endings, 50-59 is like rook+knight/bishop endings and so on.
after you master the endgames where you only get to play with a few pieces, you will understand the strength and weakness of every single piece, you will have a better understanding of chess in general than those that start their chess career by memorizing openings. i.e, i have a very good understanding of the rogue class. i achieved that by playing every single twink bracket, until i hit my "glass ceiling" (where i can't improve anymore) in the bracket and then leveling out.
i have no doubt that i will hit 1800+ in 2vs2 easily in these 70 gears when i reach 80, it's just a matter of time because i am a graduate student in mathematics and i don't know how long it will take for me to level to 80 lol.