ORIGINAL: Tow Cobra
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.
Interesting you'd say that. I have the MX450XS and it is a wonderful flier, but I had to replace the rotor blades that came with it. I haven't been able to get any of three different sets of HMX blades to track properly. I've flown it instead with MAH 315s and TRex GF blades; the TR glass blades work well for messing around, but the MAH blades are far better (of course, TR carbons might be as good as the MAH, never tried them).
Either way, the 450 flies great for me-- stable, responsive, and more durable than my smaller ones.