Hi Simon,
I've tried them all and I think that for visual observing with good portability, the 8" or 10" SCT has a small edge (no pun you lot) over the others.
That said, all have their very strong points as you read above, and if you get into astrophotography the choice will possibly be different.
It is also a personal choice thing. You will get fixations, wait and see
I have had 2 dobs, and became absolutely fed up with collimating them. So I got a 4" refractor and that is great unless you want to observe faint objects. So I got a 8" SCT for more aperture, and so it goes you see.
With a bit of luck and patience, you can get your choice here on IIS second hand for a reasonable price.
Cheers