That's all perfectly understandable.
Still, my honest advice would be to jump into the new ship.
It is quite likely that sooner or later you will run into issues with the good ol' v2.5 which will never be addressed.
Including tutorials, skins, add-ons etc. etc.
This is a good momentum to switch, since there is still a lot of activity going on around new features and changes, and chances are big that in case you have difficulties with the changes, you will get help, or your voice and opinion will be heard to even improve v3 further.
And also, I really feel that the impact, and the assumed amount of changes in v3 are being exaggerated in this thread.
I myself would say it's 90% improvement, 10% some doubts and some needed learning adjustments.
And if you still have doubts, just run a portable version of v3, and give it an honest effort.
edit:
@bossman, perhaps the moment has come to lock this thread?
Certainly not because a lot of input and opinions here aren't valuable, but the topic starters attitude, and title he chose for all this has by now had more attention than it deserved.
Anybody feeling the need just to declare that he/she will stick to older MB versions can do that somewhere else under a possibly more positive umbrella.