My Student has a top speed of 1200 I think it is but because I run it off a phase converter it's not too happy at starting up on the highest speeds. 900 is ok but I actually rarely run it at more than 650 and don't find that to be any sort of restriction. In high volume production you want the optimum speed for maximum metal removal but for odd jobs and home shop work most things will cut just as happily at lower speeds with sharp tooling for the sake of a few more seconds per job.
I always find the key is the right tooling. I use razor edged non ferrous carbide tips even for ferrous work because they cut better on small machines. Maybe for the occasional roughing job I'll use an actual ferrous tip but you can't get any sort of finish with them.
If the lathe is suitable otherwise I wouldn't give the top speed a second thought.