I can't really answer the question, but I think specialized races should be balanced against each other (without taking environmental regens into account) and be made at least equal and probably a little better overall than other races.
And then, on top of that, they should get lvl2 or 3 regen in their native environment to encourage becoming one even more.

I think the point all these previous arguments fail to address is that this oh-so-nice level 3 regen is only in Taint. Brood Viscanti cannot Taint, and nor can Nihilist Master Viscanti.

The race should not be balanced only when there is a Mage around, which there is often not. I would love to ditch the regen and have other bonuses added in, because I find I am rarely in Tainted areas except when I'm defending against raiders (e.g., Nil/Earth).

In response to Daevos:

I do dislike the way the last major racial overhaul made the specialized races only slightly better than mediocre. Master viscanti are a lot like dracnari. Imperial merian are a lot like mugwump with intelligence instead of speed and a better regen. Shadowlords are like aslaran. Elfen lord...well, ok, so the closest match to them is krokani, which isn't all that accurate. 

I don't think the specialized races should be extremely favored over the rest, but I think that they should have a definate edge over their counterparts. At this point, only elfen lord has this (which might be why there's so much griping about them: it's not that they're great, it's that they're better than the widely available alternative.) Merian had this over the mugwump back when they had +2 eq. If we went back to that, merian would have the int edge over mugwump, and they could still be an interesting counterpoint to furrikin. Things like that. The specialized races shouldn't be overpowered, but they should be the most appealing alternative in the range of similar races.

Elfen Lords have good stats, they can even safely say they go up from their base stats. High Elfen though do not, their stats get shuffled, but they do not increase or decrease overall. So in affect they are no different than a base elfen, other then a stat shuffle. Combat wise, you are best to pick any of the smaller or faster races than to pick High Elfen. This is evidenced quite clearly by the lack of High Elfen combatants.

So... let's bring all specializations up to the level of an Elfen Lord!