Shubush -
I have an AWSF18 and I'm very happy with it. I have been using it for three months now, mostly every day, and it is very solid, heavy, and free of vibration, which is what you most want. The blade clamps are like Hegner clamps and you can buy Hegner's "quick change" clamps to go with the Ax, making it much easier to use for fretwork pieces with lots of inside cuts.
The main differences from a Hegner are: the finish, where the Ax casting is a little bit pitted and rough with an "orange peel" effect (not the table of course!). Also the table of the Ax does not tilt both ways, not an insuperable problem as most scrollsaws only tilt to one side. There is no slot in the table as with a Hegner and the table inserts might have a little burring that needs filing off - that sort of thing.
I have mine on a stand and it is so quiet I can use it in the middle of the night without complaints from my partner (asleep on the same floor) or the next door neighbours on the other side of a shared wall.
So certainly I'm happy with mine, I think with your budget of £250 you could do yourself proud with the AWSF18, the Hegner clamps, and still have change for a few gross of blades. I don't see anything to touch it at the price now that Delta are getting out of the UK.
Chris