I've come to realize that, this truly is the first year that I don't really feel that I "need" to upgrade, ever since moving over to Android from Windows Mobile.
EVO - Needed more internal storage space, due to memory issues
Photon - Had 1 more Sprint early upgrade available (prior to the new upgrade policy), but needed to upgrade as soon as all the signs were pointing towards Motorola cutting off support.
Note 2 - My only major complaint about the Note 2 was the fact that no carriers in the US got the 32gb nor the 64gb version. Even though I had no lack of storage issues on my internal for the Photon, games/files/apps were increasingly getting larger and I knew that at some point that would cause an issue for me. Having downloaded files is always a better option for me both personally and in my day job. Even though I've managed, I'm down to a little over 550mb of internal storage remaining. I could hold out for another year, to see what the Note 4 brings, but with the announcement of a minimum 32gb version being offered, I definitely have to at least pay attention. There's no question I'll get the Note 3 on release day, if the 64gb version is offered on Sprint (only hesitation will be either use an upgrade from another line or pay full retail price without contract extension).