Aren't the lenses of that system the same as Hasselblad's? (at least some of them)
The 6008 cameras (which includes the 6003) use the PQ/PQS series of lenses. These were made for Rollei by Schneider and Zeiss, and some of the Zeiss ones had the same design as the Hassy lenses, although the integral shutter, lens mount and electronics are totally different. The Schneider lenses are typically a step better, being a more modern design. It was a wonderful period in the 1990s when Mandelmann owned both Rollei and Schneider and had a lineup of lenses designed by Schneider over about 5-7 years that were just the best in medium format. They hold up quite well, still they are wonderful lenses - use them still today with digital back with great success - the only one I ever questioned was the slight degradation on the far sides of the 40mm - the rest are tack sharp, corner to corner. For example, a look at the MTF for the 150 f4.6 shows a distortion curve that is just flat zero. Some have mild CA and a gentle bit of distortion, easily taken out in post.
The Zeiss lenses are nice, have a different look. They are typically less sharp wide open, but snap into sharpness around f8. Their distortion curve is more complex. Recently using the Zeiss 250, quite a bit smaller and lighter than the Schneider 300 Apo. At f11, there isn't much between them.
As to complex cameras? The 6008 is not all that complicated. Had a couple, they were fine - but with digital backs, prefer the Hy6, and have been using one for the past 10 years. It uses the same PQ lenses - so those I bought in the 1990s (now 25+ years ago!) are still used. The Hy6 has great focus confirmation, so it handles focusing manual lenses quite nicely. The only issue is the camera's knobbies get a bit funky with lack of use, but the rest is just fine. IMHO, its what the Hassy should/could have become - good features, ease of use, simple interfaces, built in a modular platform. Too bad more people don't know.