More sun is good for apples. But being in a pot does make a difference. The pot can get too hot setting in the sun. That can damage the roots. So shade the pot in either location. Then there is the factor of watering the potted tree. More sun equals more need for water. Solve those two issues and more sun could be a plus.

6 to 8 hours should be fine....to aid growing and fruit production it really should be in the ground.

Thanks for the feedback.

I only have about a 10ft gap i could plant it. A 10ft apple tree on one side and a 20ft plum tree on the other. Do you think it would still be beneficial to plant it compared to a large pot or would it be too much competition? plus there is a fair amount of shade from the plum tree. I always keep the pot and trees well watered and fed.

Sadly only a small garden so there's no other planting position.

Guessing you are in the UK, Jack? If so the heating of the pots is less of an issue than it would be for people in much of the US. Also, bees fly quite a distance so I'd probably put them in the warmest spot from the off and not wait for pollination.

>>I only have about a 10ft gap i could plant it<<

I would...less hassle and you'll enjoy it for many years, trim it low....in pots it's very short term.