I started with a blade CP and then went up to an MX400 Pro. This does fly very well when you tune it correctly. I have the MX450 which has all of the upgrades (metal head, carbon fiber parts) but I've never found that I could get it to fly nearly as well as the MX400 Pro so I'd steer clear of it. Also, if you watch, the price on the 450 has steadily declined a lot so maybe it's not selling to well whereas the price on the MX400 Pro has been about the same for over a year.

Good luck, upgrading is definitely the way to go and you'll advance well as a pilot when you do.