I've used the hand-crank like that as well as the electrice conveyor type, and was most unhappy with both. They're right, both kinds are very tough on casings, I lost (if I remember right, it's been 15 years since I messed with one) around 25% of my run to the machine.
I portion everything by hand and get it close to weight manually. I don't worry about being exact, as customers like the 'artisan' type sausage, and I don't ever do a batch over 100# at a time, with a retail run of 500# a day being the most. It boils down to how important is exact portioning to you, and is there a way to do it by hand that doesn't eat up your time.