It's not the load, but the service cycles. If the price is right then go ahead, but if you can buy new 5855's or equal for less then you're getting the short end.

Don't get me wrong, the 8711 can carry a heavy load, but do a some searches on JR 8611 nd 8711 gear wear, servo chatter, and hunting neutral. I was a JR guy for years and that's why I changed over to Hitec after several years of separation from them. I still have a lot of, and use, the 8611's but I know that anyone of them can start to chatter at any time. I have enough servos that I won't lose but a days flying time if I have to pull a few and send them in for repairs. Been there, done that already.

If you can deal with repair issues and not get hurt on flying time then go for the 8711's if the price is real right.