Ok, So I'm in queue for the map right now, So I think I've a small break to right down my humble opinions
I recently saw the edited post regarding the reasoning behind these changes. First off, I'm not sure what you guys meant by "we have some idea of how much better mech will be". Is gthere something else in the works? Or is there not? Right now though, It sort of feels like we are being strung along.
The last paragraph perturbed me quite a bit though. It seems that this buff is not really made with mech in mind, but "bio-mech" instead. Which here means add hellbats, which kind of feels-well, slightly insulting. It seems that you guys just want us to build factories in tvp just so we can make the equivalent of a fire bat in a bio comp. To which I ask, why is the factory a necessity? Why not just remove the damn thing, if over half of the other units are just going to be ignored?
I know this is not the greatest way to start a balance suggestion or some amount of discourse, but I just wanted to mention that.
Now, onto my thoughts of Bio-Bat.
We have seen Bio bat in some games (Mostly Innovation's) that center around hellbat-marauder. IN fact, Day9 Did a few nice pieces back in May i believe. In does seem strong in timing attacks, but as a late game transition it seems shaky.
Innovation in those showcases showed us some nice two base timing attacks that lined up with the more conventional timing attacks. That is, strike at 9-13, do some damage, and then proceed to drop and deny tech. However, as the game progressed and the protoss player climbed the tech tree, we saw hellbats being replaced by marines (and eventually ghosts).
The main reasons it seems? That late game tech toss has is abundant with splash. Hellbats, being low range and slow, don't stand up terrifically well to aoe (which toss has in abundance). So they usually melt before they can be used to tank or dish damage to zealots. They don't split well, don't dodge storms, and get zoned by collosi pretty well.
Bio right now relies on its mobility to win these battles. The hellbat seems ill equipped to fill any sort of hole due to its mobility limitations.
Right now, The ultimate bio comp seems to be ghost-viking-marauder-medivac-raven.. Ghosts seem to fill holes much better than the hellbat does (zealot counts come to mind) due to their ranged attack, solid +light dps, and the utility of emp and snipe.
Trying to divert resources and time to getting a "hellbat-transition" up seems foolhardy. Considering the Ghost preforms the duties of the hellbat much better and then some.
Why exactly would one divert resources (And hundreds amount of gas) into throwing down three or four factories, and researching blue flame, only to squander it later? One could use that capital to accumulate ghosts instead!
Furthermore, we're still playing bio, and there has been overwhelming feedback that this games needs variety
Mech has the tools, it just needs some tweaks.
Imho, the best way to give terran a chance in the late game is to give them a choice-be super aggro and play for the mid game, or try to balance aggression with preparation for the late game with mech.