[MicroBob]

lessu - exactly correct.
You really are getting over 100% RB on SOME of the hands you are playing. But this is true at .5/1 or 1/2 NL also. When a hand is raked exactly $0.40 or $0.50 all the SN's are getting over 100% RB for that also.
Unfortunately, not all of the hands are raked exactly at that amount.

It would appear from his post that OP thinks he is getting a true 100% rb ALL the time by playing 1/2 limit and did not look at his average rake per hand to determine his true RB.
I can't help but chuckle at thought that he was grinding all those hands on those tables with the mindset that he was getting 100%+ all the time.

However, it is true that he is getting a really good RB rate there.

I don't think his estimate of $20k per month is correct either. At least not just in rb anyway.

Even a fast-moving table should be in the 40 VPP/hr range.
At 5.25 cents per VPP this is $2.10 an hour in RB.
So at 10 tables you are pushing around $20/hr in RB.

So I'm really not seeing how he can get to $5k/wk playing 7 hrs of 8 tables.