The X55 is a good joystick.
What I would say is that you will probably need to lube the vertical shaft (oooer) to avoid sticking issues.
That aside, it feels good but is plasticky in comparison to the Warthog. The Warthog feels like a real joystick that has been nicked out of a plane, and they are currently available for £239 from Overclockers which is a brilliant price. However, the 'hog may be too stiff to move for some, and the loss of twist could be a huge loss. The build is far better than the X55 IMO. One possible consideration is the switches on the hog are mainly real switches whereas the x55 are toggles. This could be a matter of taste. It is necessary in the x55 I guess as it has mode switching, which in itself is nice and may be useful for docking etc.
I'd encourage folk to try both if possible.
The best bang for your buck was the X52 pro at 107.99 from Amazon, but that price fluctuates. It will be interesting to see what price the X55 is compared to the '52 (from Amazon). I still think the 52 is the most ergonomic, but wish it had more buttons.