Did you have the new one or the old one? I presume since you've had it a while, and since they are referred to as "new" and "old" on Amazon, that you had the "old style".
Old:
New:
Regarding indestructibility, the DT770s are, indeed, built like tanks. I've abused the snot out of them, and they've never broken. I think that's one of the things that makes them a studio staple.
The HD600s, if I recall correctly, have a metal strip through the band, so are therefore that little bit less prone to being broken.
The Sony MDR-V6/-7506 needed to be treated a little better (that either of the above), because they had so many joints so they could be folded together, but I think most people know that and therefore treat them with a little more respect.
I think it's a fair question to ask how sturdy it is, although I'm not going to base my opinion on one data point.
So since you own one, what sort of power demands does it require? I know the HD600s scale like mad -- the better you feed them, the better they sound -- and the above-mentioned Sony headphones hardly scale at all -- they sound pretty much the same no matter what you feed them, unless the amp can't handle lower impedance phones.
And how would you characterize it? Is it a studio headphone, "accurate", or a home high-fi phone, "euphonic-ish". Bass-heavy? Scooped? Bright? Veiled? etc. I looked at the frequency response, but I prefer subjective impressions.
The DT770 are notoriously bass-heavy headphones, but with sufficient power, it can be controlled and deep. It does have a slight etch to it which I at one time got used to because I listened on the Creek OBH-11SE, a FET-based headphone amp, and later on tubes, and both those amps helped ameliorate the etch.