I'm a Newbie hobby trading for last 3-4 weeks.
Since the Dwolla connection to MtGox was stopped, I've been using a US Bank -> Dwolla -> CampBX -> MtGox. I've only transfered lower amounts (< $1K/day), but it transfers from Dwolla to CBX instantly (for me). Then buy bitcoin on CampBX and then transfer bitcoin directly to MtGox (or other exchange), CBX will charge you the 0.0005 BTC miners transfer fee, but that $0.06 is very low. Mt.Gox has been showing the bitcoin received and ready to trade in approx 1 hour.
I've been using
http://bitcoinity.org/markets/campbx/USD to see the transactions / price. My take is that although the overall volume is very low compared to MtGox, it seems you can purchase < 50 BTC easily and at a reasonable price relative to other exchanges.
Getting the USD back to a US Bank could be the reverse (send Bitcoin back to CBX, sell and USD back to Dwolla) this can be the lowest fees method. Depending on Coinbase price, Coinbase is also an option back to US Bank through ACH system (although 4 business days delay sucks) plus 1% fee. Tried this only once. I sent a message to Coinbase asking that they add Dwolla instant transfer support, like CampBX.
I haven't done anything at higher USD$ amounts. I am verified with MtGox.