1) I like the autorouter. You can give each net a different size of tracks vias and als spacing. I always start with routing things that are critical first. Another trick is to define keep out areas and just load a part of the net (best of a sub sheet) let it autoroute, then do the rest manually.
2) Database is growing, but as mentioned above use "compacting" option; no problem
3) 3D in my opinion is more of a gimmick. It works under win2000 Nt XP but freezes under Win98/se
4) We have some problems with simultanious use of Adobe Acrobat and Protel. But it never caused us to loose data.

Werner

Besides: I like that it does not use a dongle