I believe with the L2501/HST you will get an independent PTO, where the PTO speed can be varied independently of the tractor's ground speed. This is desirable.
That independent PTO coupled with the HST allowed me to get into the summers growth of weeds in some places taller than the tractor. Although the first time through, took a while at slow speed, the L2501 was up to the task and now I can see to tidy up the edges this fall. Great little tractor! I like to leave the native salt bushes for quail cover, and although they're a pain to mow around, the HST allows me to back in and then finish up with a brush scythe when needed.