I confess that I quite like them, and use the Jeppessen 1:500,000 charts out of preference for long distance flying - the airspace and airfield data I find much more user-friendly (plus they are from much thinner untreated paper, so fit into my kneeboard better and I can draw on them in pencil).
But yes, the topographic data is undoubtedly their weakest point. But having used them for about a year now and got used to the style, I find it good enough for accurate VFR navigation.
I did once make a complete fool of myself by not noticing the subtle difference between a VOR and a TACAN on the Jeppesen chart - you do need to take time to learn a new tool!
G