Which autopilot?
The conditions you find most uncomfortable for hand steering are the same conditions that tax the autopilot. You don't want it to crap out when you need it most. That said, one would be well advised to avoid the most common mistake made by those who purchase autopilots. That is installing one with an advertised maximum limit that is close to the displacement of the boat. Advertising claims being what they are, and reading comments on various boards, it's a fair guess that the ratings are based on optimum sailing conditions -- the kind one is unlikely to be experiencing when the help of the autopilot is needed most. When you've decided on the size of the unit you think will do the job, move up to the next size. It's much better, and safer, too, to be relying on a unit that is loafing rather than one that is consistently operating at, or beyond, its designed limit. Mechanical breakdowns are directly related to the amount and duration of strain involved. There may come a time when you wish you had gone for the bigger one.