I bought an X70 and really and truely never give it a chance at first. It took me a long while before I warmed up to it. I decided that I wanted to learn the machine and started using it exclusively. Once you give into the machine it will treat you right. I love this machine for the styles of hunting that I do.... which is mainly swamps, open fields and old house places. In trashy areas this machine shines. The prospect mode is also killer in the open fields and will find items DEEP!
I bought my X70 at the end of 2008. I was kinda disappointed that Minelab released a new machine not too long after I got this one and then the price on the X70's dropped some. Other than that I don't have any regrets about buying this machine. I have gotten to where it's the standard machine that I use.
Right now I have the 9" Concentric 7.5 kHz coil, 9" Concentric 3 kHz coil and the 6" DD 18.75 kHz coil. Soon I will be getting the 10.5" DD 7.5 kHz coil.