I had mine (not the plus!) for about a year now and scanned five or six books each 200 to 300 pages. I had no problems with the software under Win2k or WinXP.
It is not very fast to start because it takes a while to warm up, however once it is running its really fast.
So far I have only used it with the supplied software, which takes some getting used to. However once you get the hang of it it works very well. The software stores each page in a different file, so there is no need to use any third party software with the scanner.
For books that are not printed very evenly I found it useful to crop out headers, footers and page numbers from the TIFF files with PhotoELF, before running the OCR tool. This way editing in MSWord later is much quicker. After some generic macros to eliminate fixed page turns etc I get less than one OCR mistake per page, which makes for good reading.
This is a very dedicated machine to scan books, this it does better than any other scanner (scanning speed is high, books almost line themselves up properly, you can select the area of text you want, books are flat, the big buttons allow you to start the next page very fast).
It is not as good to quickly scan an individual sheet as the warm-up time is long and it does not do very well with photos, the color separation is poor.
In my opinion the only thing missing is a document feeder option.