I restarted because I needed a new, fresh start. I unlocked everything and the game kinda got boring. Yeah, I brought some stuff that took a long time to get, but overall, I started from scratch. I'm really glad I did!
If you do restart, I could hold some stuff for you, if you want.
I restarted my original town after over a year of playing. I had been seeing some amazing dream towns which made certain things like the placement of my cafe and other issues seem more obvious than usual. Still, I had a lot of stuff so I didn't give in until my favorite villager moved out. In anger I reset without saving anything.
If you search Catmandu in dream towns you can actually find all of my old towns. I ended up restarting a few times, though not all of them were intentional. (SD card issues, anyone?)
Anyway, my issue is that when I restart I don't really have the patience to wait those first few months for the better stores and such so I set my clock back a few months and work toward the current day. I'm hoping that once I get to the current day I'll be able to stop TTing and play day by day because it really is much more fun.
There are things from my old town I wish I still had. If you insist on resetting I recommend choosing a few items that make your town feel "like home" and having someone hold onto them for you. It might make it a bit easier to suffer through those first few months where you have so little.
I restarted too, and even if it took a few tries to get a town in which I really felt well, it made me realize that some villagers I had in my old town, such as Poppy, weren't so special, but what was special were the memories I had shared with them. I had found Poppy a few times, and I stayed a couple or two days in the towns where I had found her, but I ended up restarting again. Poppy was a "meh" villager, but the initial cuteness she showed to me back in December when I started my old town, Esparta, and the sweet memories and presents she gave me made her the best friend I had back then (my real life friends used to be a bit distant back then, but now it's OK). Now I've found a town where I hope I can stay FOREVER.