I think another good reason for the slant beds is to even up the loading and hence wear on the ways. A conventional lathe bed always wears the front way more heavily as this takes most of the load whilst cutting. Bringing both ways forward of the centreline of the chuck means they are sharing the load.
I am not a professional machinist, so my observations are based on limited usage. There are pro's and cons with the slant bed. Big plus (overrides everything else) is the available swing in a reasonably sized machine. Second is that it is very easy to keep clean, due to the stainless covered slant bed. One downside is that the rear way is sort of out of sight out of mind, so harder to make sure it is clean. That said, as the shield goes almost entirely over it it does not get too covered in swarf. The tailstock locking bar had broke and had been repaired by a previous owner. I had to do quite a bit of fettling to get the tailstock to slide smoothly without the locking plate snagging on something. It's ok now, but the locking bolt always takes two bites with the spanner, the lever setup on the colchester seems better to me. I need to make up a board to put under the chuck area when changing chucks. That needs something making up as you can't just drop something across the ways like a conventional machine.
I don't know how you are supposed to level the machine. I did my best by making sure the cross slide is level at either end of the bed, and it was level along the length. I would like to chat with any other owners, especially anyone that might know of any parts that may be available, or a machine that is being broken. Mine is the long bed version which I have to assume is relatively harder to find than the standard length version. I've found plenty of pics online of the 24 jobs, but only one pic of a 36" model like mine.
I really like the lathe. The dials are really easy to read, which suits my less than perfect eyes. I like the quick change box and the general sturdiness of the machine.