My current 4041 uses the hydro for the loader, it's a bit slower than my MF 1855 with Johnson Workhorse and separate pump, but reall plenty fast for normal work. The only time it's noticeable is when rolling and lifting, then the bucket is slow, but that's not a big deal.
A lot depends on the duration of the job. When moving a few yards of dirt on a beautiful summer day, a few extra seconds for each lift here and there is inconsequential. My 1655 will move 12 yards of material from the front yard to the back yard in a bit over an hour. It's just a wee bit of a different tale at -20° F after 4 or 5 hours of driveway clearing.
Aside from the few extra seconds for a normal lift is the extra time required when using the hydro to push the bucket against the snow pile so that the snow can be piled 7-8' high with a 6' lift capability. A hydro under load requires more fluid from the charge pump leaving less for the loader.
Then there is the issue of available pressure. Max pressure for most GT hydros is about 1000 psi. I run a bit higher with the auxiliary pump.