I've had one for quite a long time. I like it, even if it is a bit fiddly sometimes.
I've been using it with Diafine lately, so the fill time doesn't really matter. Previously, I've been using it with high dilution Rodinal with relatively long development times (10-15 minutes), so the long fill/drain time (about 30 s) hasn't seemed to make a difference. I do put the fill and drain on the same side.
It has been my experience that you really do need to assemble it carefully lest the film slip out of the slots. Also, the lid does need quite a bit of pounding to get it on tight, lest it leak a bit.
Is it perfect? No, but it's been the only daylight 4x5 option that hasn't annoyed me badly.