I don't like them. For me, all I need is an adjustable bench and a set of dumbells for home work-outs. I have friends who have had them - they are nice and are good quality. I get a better workout from free weights though.
I have had the oppotunity to play with
these though, and they were really nice.
My only complaints were:
1 - kinda pricey, but not when compared to individual dumbell sets and not when compared with a nice home gym.
2 - when only lifting lighter weight (which I do a lot of unfortunately) they were a bit bulky, but nothing you can't manage.
The important thing for me is to find the commitment and consistency to make it rewarding. I like to lift light and then run - a little every day. It keeps me fit. I'm not the strongest or the fastest, but I do well at both by comparison.