That thread is really interesting for me.
I'm playing 1-table Sngs at Tilt thoses days, in a dilletant style, saying one at the time, and i would like to have some advices. First, i chose to play $5 HORSE 8 players Sngs (no turbos) which paid top 3. I'm doing well there but didn't play enough games yet to have any real useful stats. Let's say that i finished 7/9 ITM, with a profit of 3.83 per game. I stick to $5.50 BIs and my BR now reach +$230 and i will stay at that limit for next months, no matter if i have my BR growing better than i thought. 
I will probably wait till it reach $500 (if ever happening) to move up at $10 tables.
So what you guys think about my strategy? Am i too conservative? i read somewhere else that a player should change move up when it has 40 to 50 times the BI, is that the way you're doing?
Here is a piece of an article i read, which might be useful to everyone:
So how can you protect against these swings of fortune? The answer is to ensure you have a big enough bankroll to withstand them. Most Pro SNG players recommend that the minimum requirement is 50 buy-ins for the level at which you play. Others suggest that a 100 buy-in SNG bankroll will effectively shield you from any thoughts / concerns about variance.
Here is what your 50 buy-in Bankroll should look like for the various levels.
$5+50 SNGS -$275
$10+1 SNGs - $550
$16+1 SNGs - $850
$20+2 SNGs - $1100
$25+2 SNGs - $1350
$30+3 SNGs - $1650
$55+5 SNGs - $3000
Another thing that bother me is that i can't find any consensus when calculating ROI percentage. Some will say that's profit (with or without fees)/BI (with or without fees, depending on versions) x100. Is that the right one or should i keep searching the right one. 
Here is another piece of an article on the subject:
The common consensus is that today’s chart should look like this:
11s - 20% ROI
20s - 15% ROI
33s - 10% ROI
55s - 8% ROI
109s - 7% ROI
215s - 6% ROI
Not my level of BI, but not my % either.