It is quite some years ago that I tested it and don't have ready access to the data, but I do recall it was less than 5400 using the LSI USAF 1951 resolution target. I should haul out that scanner and retest it (when time permits) now that SilverFast 8 supports it. Regardless of the exact number, this scanner produces very fine detailed scans - every bit as good as my Nikon SC5000ED, but much slower.
The USAF 1951 target is not very well suited for resolution testing of discrete sampling systems, a slanted edge target is, or a film shot of a Star target, depending whether one wants to test only the scanner MTF, or the (film+scanner) system MTF and resolution.
When I measured the options at the time, I got the following resolutions; LS2000: 45.4 cy/mm, LS4000: 62.1 cy/mm, SE5400: 76.1 cy/mm. The SE5400 beat them all at resolution.