Going back to my Tarmac as a daily commuter and will
 

let my HardRock be the family fun bike. I love my new HardRock and like being able to hop up on the sidewalks when traffic gets to be a bit much, but even with new tires the Rock is a slug on hills and is killing me. I guess I was expecting too much from a mtn bike commuter.

So I'm now in the market for a new durable cummuter that has some speed; can anyone suggest any bikes that will fit the bill? I'd like to have a commuter that I can load down with panniers, is still fast, mobile and durable enough for inner city traffic; and yes it needs to be able to climb like a mountain goat.

Sounds like a cyclocross or touring bike would round out your stable. I chose both, a Jamis Aurora and a Specialized Tri-cross.

Thanks Hot Potato, I don't know much about the Jamis Aurora but I like the fact that it's steel; now I just need to find a dealer so I can test ride one. The Tri-cross seems to be more expensive and is Aluminum; I'd really like to have a steel commuter as part of my stable. Thanks again for the suggestions.

IMO there is nothing better than a good sturdy steel commuter, I can load the crap out of my Cross - check that is fully loaded with racks and fenders, and it still rides like butter and handles like its not carrying any weight.

I upgraded from my mt bike commuter to a steel frame cyclocross and haven't looked back since.

+1 on the cyclocross bike. If your looking for steel I would also suggest looking to Bianchi and surly. They both carry steel commuter friendly bikes. The latter seems to be a fav for commuters here.

How much you wanna spend?
Cause I'd suggest an Rivendell Atlantis for really loading it up or a Rivendell A. Homer Hilsen for something closer to a road bike but still fits fatty tires and can handle light loads. Both have comfortable touring geometry.
But you probably don't want to spend that much.

Salsa Casserole. I love mine.

Thanks, I actually looked at the Rivendell a bit and was very impressed by yours, beautiful bike. The price is not that much of an issue but I'd like to stay under $2,500; about what I have invested in my Tarmac would be comfortable give or take. I plan on commuting a lot so I can justify the price if I really like the bike.

After someone posted a review recently of his Salsa Casserole I put it on my short list. I just need to find a place in Atlanta where I can test ride one.

Out of left field...if you want something different and with some bling, have a look at a Kona Kapu. Italian steel, plenty quick, very stable. I picked one up recently and love the ride. Tons of clearance for larger tires (I'm running 28s and it looks like 35s would fit), rack mounts, and a very classic look.

I wouldn't leave one locked to an outside rack with no security, though. Not exactly low-key.