I'm somewhat disappointed also. It's very much a big screened One, but it does take a step back in some areas.
1) Snapdragon 600 - It's not a step back per se, and it's not a bad chip at all, but the expectation was Snapdragon 800 (at least that's what I was hoping for). It offers improved performance and battery life. I feel like it was supposed to have it, but didn't for some reason.
2) Storage - I thought we were done with high-end phones having a 16gb option. The One is 32/64, so this is a clear step back.
3) SD card - Seriously? It has one? That's terrible and is a definite step in the WRONG direction for HTC.
4) Design/build/materials - It looks much more like a larger One Mini than a larger One. Same plastic rimmed edge, the trademark difference between the One and One Mini. Actually, maybe that's what this is, and if that's the case then yes, this is a step "up" from the Mini. But then, so is the regular One.
5) Camera - No OIS (optical image stabilization). Why not? They already have the camera module in house.
All-in-all this is not a new flagship device IMO. This is a way for HTC to try and get a small chunk of the "too big" phone market. It's not a Note 3 competitor, though. You lose too much getting the Max vs the Note 3.
The best we can hope for is that this is priced really well and represents a great deal for those that don't care about stylus support but want/need a larger screen.
Sense 5.5 does look to have some nice changes, though, and I do want that on my One.