I have just bought a canon XL-H1 (well back in July, but have only just started using it) and have tried out all my old XL2 accessories etc, including the FU1000 viewfinder. With the stock colour viewfinder, the camera's peaking function is 'ok' but does seem to just make everything harsh.

The FU-1000 has it's own peaking control, but again on the XLH1, this seemed just 'ok'. Now, put the two together (and get the mix right) and focussing is incredible. You can clearly see a very sharp peaking image exactly where the focus point is, very very clearly. Totally clear focussing in this setup. Just thought I would share this.