playing at a higher buyin level and more tables

[player1]

i realize going from the 30s to the 50s and 8 tabling vs. 4/6 tabling will both decrease your ROI). i have a pretty decent ROI in the 30s (around 17% in the last 1100 games), but it seems to dip significantly if i either move to the 50s or go to 8 table sets (not both). too early to tell, but i think make more at the 30s and 4/6 tabling. my play (ABC) is more or less the same with either of these modifications.

has anyone else experienced the same?

thanks,
jc