have you got trapping on? that can slow it right down as you would expect.
At first i didnt like XMF but after using it for a while it is really good, the only thing i havent been able to do in it properly is creep settings, they are a bit of a nightmare, at least for me.
As far as the different types of impo templates, I never use the layout, just the stripping, if you want to log on to my system and have a look around it (its only v3x) pm me and ill give you a remote log in.
Its solid points are everything is in one package, impo, rip, export, room etc. Just and example, you can set up a saddle stitch book with a cover form a job template in seconds, then send a pdf low res proof to one folder for email proof, high res tif to a inkjet printer for hard copy, very easy to do. I like its number of options when it comes to replacing a page in a book, or just replacing a file, a few clicks and then save.
I used to worry about RGB images in files using other rips, but now I dont even bat an eyelid at them, it uses whatever icc output profile you choose to convert the colour.
For the price and reliability I reckon its a good buy, ive heard of others with database problems etc, but I have never seen it.
Dont expect to be able to export your preps templates perfectly into xmf, i had hundreds of them and just started again in XMF, it was quicker in the end.
Cheers,.