Re:
Yeah I use it about as much as ebay, mainly for cycling bits and bobs, shipping can be anything from a week to a few months (but usually weeks). I've not bought anything of high value on there yet, but I've had zero issues thus far with my purchases.
As above, check out seller ratings and delivery method /times.
Try ordering something cheap and see what you think (and like Fluffy says, do it via Topcashback and pocket the 5% saving (it was 8% until recently)).