As an example; at Level 20 without Rec as a superstat, the tooltip for Regen said it heals 62 per tick. This was with somewhere around 25-30 Rec total. I had a +5 Rec secondary item in my bags, slipping that on bumped it up to 64 per tick.

So I would say that it actually scales fairly well. +2 per tick might not seem like a lot, but for only a 5 Rec difference it's not bad. You have to remember also that it ticks every 2 seconds, and it can gain a max increase of another 250% depending on how much you're getting attacked (and attacking).

Not sure, but I think all the people stating it doesn't scale well dropped it a while back and don't actually have any recent experience with it.

Lvl 40 with rank 3 and 274 rec I get 306 health every 2 sec.

Was the character above level 26?

On my 21's i have 120 recovery and getting around 1 hp regen per 2 points of recovery at full strength(250%) you should get about 1.25 hp regen per point of recovery or 2.5 hp's for 2 points.

It'd be nice if it worked like that for the sake of estimation, but I believe that the scaling of focused characteristics alters depending upon level and thus makes it unreliable. For example, 5 points of DEX at level 10 give a bigger bonus to Dodge/Avoidance than they do at level 40. Pretty sure I read some research done on this by another player posted around here somewhere, and this was even before the last patch of characteristic adjustments.

Regen unlike say invun isn't a constant value protection. Where invun will knock all damage pretty much the same, regen is limited to the 250% bonus so as the damage gets higher and higher you mitigate less so by keeping a certain amount of recovery to offset the damage increase that mobs do, where invun increase stats to keep the same protection reguardless of how much the damage increases. It could very well be constant 2 to 1 ration at rank 2 maybe but to know for sure would have to do alot of testing.

Now i don't got a 40 to test this because i am lvling 15 characters simultaniously but just get a few 40's to report how much recovery they have with regen lvl and rank then have them do the same without equipment, just 10 people doing this should be able to get a general understanding of how much a bonus it gives at 21 across my few toons that have regen and recovery stats at rank 3 is seeing around a 2 to 1 ratio but that is just swapping in less then 5 values between piece i haven't analized it farther.

Looking at the lvl 40 person's stats in this thread if they could post what thier recovery is without equipment and how much regen could about how much difference it is. If they get a 2 to 1 ratio that means with 0 recovery they would have 169 base regen with 137 supplied by recovery from the 274 recovery. Now if they took a intial and talents for recovery getting the main recovery, and 2 5 point recovery talents you looking at around 30?? base recovery. So with no equipment they would be 184 regen without equipment if 2 to 1 ratio. Would be interesting to find out since regen scaling seems to fall off a high lvls if you don't focus on recovery might be the problem.

Just to elaborate, when I speak of Regeneration rates I only talk about the base. The maximum rate is the same 250% regardless of your base health per tick, so I don't see any point in complicating matters by including it.

The characteristic point breakdown I was referring to above, incidentally, is in the Math Behind The Numbers thread that is floating around the first page again. They're rehashing things since that last patch, but it seemed that despite some different numbers the formulae follow similar diminishing returns patterns.