i putt on an instep, and although i haven't added the inner chains i could put together myself, it doesn't catch so hot. you really have to think of practice as just how good putts feel... and make sure you feel okay when they blow throw or swing completely around the tray and slide out. i got mine for $68 shipped, which i think is no longer an existing deal. it's held up awsome considering i live a 1/2 mile from the ocean and everything rusts. it's just rusted a tiny bit after a year.
the skillshots totally catch everything that gets in, plus they're easy to move around... in a way i wish i had one of those, but then again a year later it wouldn't still be in near perfect condition.
both would be great

but i need a higher paying job first.