Hi,
Rather than starting off with my own mining rig I'm thinking of joining a group buy. The thing is that these invariably need payment in BTC, so far I've checked out coinbase and they seem to be a reasonable choice for buying my coins. Can anyone who's used them comment either positively or negatively?

Also, group buys - especially on this forum. I'm willing to give one a go given the relatively small sum I'll be investing but again, has anyone had good or bad experience of them they'd be willing to share?