Hand filed for many years, taking my chains to a shop once a year to even up the cutters. Then the guy at my shop seemed to get really burned out on the whole shop/dealer thing and would take two weeks or more to sharpen even one chain. I'd go in, he'd be smoking a cigarette and drinking coffee. He always wanted to chat, he could go on forever, never leaving the counter chair except for more coffee. I had to drive 40 miles each way to get to him. Of course, I had to go back in two weeks. Sometimes he still didn't have them done and I'd wait and chat while he did it.
Then I bought a Maxx from Baileys and it paid for itself in a couple years. Plus my time savings of not driving so far. And, I found that I kept my chains even sharper than when I hand-filed, because I could switch on the Maxx, do a couple chains in no time at the end of a cutting session and keep them ready to go next day. I even put a mark on the wall by the Maxx and kept count of the sharpenings to know when I'd paid for it by not going to the shop. Just for fun.
Yes, you can hand sharpen just fine, with practice, and files are inexpensive, but nowadays I use the Maxx about 90% of the time.