Different download sizes & constant crashing

First, I do believe that you are correct with regards to the download size. I play on several devices, and it seems the HD ones have the larger download. That being said, I have not found any way to change this. Which leads to....

Second, I personally believe that the HD devices are the ones that choke on the game (read: constantly crash). I too have an HTC One, but have not had too much trouble with crashing. I have read of someone using a nook HD that constantly crashed rooting their phone in order to change the resution which effectively fixed their crashing issue. I also have a nook, and can tell you first hand the crashing is constant, but on my HTC, it only crashes about once or twice a day. I am finding that it seems to be getting worse as I add content, so I fear I will be in the same boat as you soon.

If this is the same problem, it appears that it may be a resource issue of some sort as your town reaches the larger size. I have a few towns, but my main town is the only one that has this problem, and it has most of the buildings and characters...including premium. There is more on this in the bugs section of the forum.