I admit that I am an upgrade junkie. Eversince I laid my hand on my first PC (bought by my dad using motorcycle funds) I have tried to upgrade and squeeze every bit of it. Windows is not really fun in term of upgrade since I felt it is only for catching up bugs. Another think is MS product tend to bloated and become slower each time the upgrade went public. The exception might be Windows 7. It feel snappier than XP let alone Vista.
Recently my attention have been directed toward Blackberry. With this device, each upgrade is make the device better (overall). Sure it has some quirk like the disabling of keypad lock on 8900 running 5.0.0.411 and 461. Every upgrade gave a squeeze of memory, better memory management, snappier performance, better battery life, and so on.
In line with my upgrade addiction, RIM has been releasing versions of OS 5 rapidly through many cellphone operators all over the world. And do not forget the leaked versions too.
Yes I am an upgrade junkie and RIM is the dealer.