So I just started messing w/ 2.5 for about 10 minutes. Space used to be the shortcut for “Add” and it seems I can’t manually edit that shortcut. “K” is not only not Knife anymore, but wtf is up with the new knife cut? Its a joke. Remember before you could click your start cut point and end so that you could make a straight cut. Now it forces you to jitter your hand from point a to point be coming out with a non-straight cut.
I’m mainly mad about that knife cut issue. I also have not been on the forums much so these things might have been discussed.
I don’t know about the knife but the “Add” menu shortcut has simply been changed to Shift+A.
It’s also available from the “Info” window at the top. And you can also add the “3D View: Dynamic Spacebar Menu” add-on to alter the default.
Open the Preferences from File > User Preferences or by replacing the current work area (e.g. 3D View window) with a User Preferences window, then go to Add-Ons and 3D View, enable the Dynamic Spacebar Menu, download the script from the provided wiki link and open it from the Install Add-On… button.
2.5 is not perfected yet, but you should learn how to use it, because every version from now on is going to be based on it, and there is alot of cool stuff, like adding clouds, that you simply can’t do in 2.49. I also found it difficult to figure out where everything is, and how to activate certain commands, and I am still learning. I am glad I finally dove into it though. There are certain things I still prefer to do in 2.49, such as retopo.