OBface Soller is fabulous! We went to Mallorca 4 years ago and I hated so wasn't really looking forward to this holiday, but I have found I love this bit of the island. We're staying in the town but going down to the Port most days. If you are into any sort of activities, look up Tramuntana Tours. Andy is excellent and we've booked a few things through him. My son and I went Coasteering last week with them and even though I hate jumping into water, Diego, our guide, even had me doing the 13m jumps. 
If you like walking, going out at the crack of dawn makes it completely manageable. We went up to Cuber for 6:30AM one day last week and were up at the top of the Puig de l'Ofre by 8:00 and back to down in the square in Biniraix via the Barranc by 11:00 (didn't use a guide for that - the walk is clearly sign posted).
In town, if you want a lovely, different eating experience, go to Ca'n Llimona. It"s one woman and all she does is ravioli with salad and cheesecake for dessert. It's like eating in a friend's very beautiful garden. There's no menu but she does do a few different flavours of ravioli so you can choose one or a mix. She only seats 6 at a time in little tables scattered about her garden so do book.
We walked to Fornalutx one day (there's also a bus a couple of times a day) and had lunch at el Tores- fantastic views!
If you want a gentle walk with some views, 30 minutes gets you up to Sa Capelleta, the prettiest chapel you ever did see. Google maps shows the way, but ignore the zig zag road and look for the steps/path up (is sign posted) and it'll save a lot of time. We did it close to sunset when it was cooler so couldn't enter the chapel, but you can peer through the windows and it's been done to look like a cave- gorgeous little place with great views over the town on the way back.
Down in the Port there's a great little cafe for smoothies/fruit juice and also cake/fresh oj/coffee for 6euros. I can't remember the name of it, but will be back down in the Port tomorrow so will look it out again. We really enjoyed dinner at El Sabor which isn't in the greatest position on the port- does have a bit of a view- but the food was really good. Most places do need booked a couple of days in advance.
The tram between the town and port is ridiculously expensive. We've done it once to say we'd done it, otherwise are walking (but we are walkers!) and have taken a taxi once. Taxis are a bit hit and miss at the stand- not enough of them. It's easy to get the bus from the Port to the town but the other way it fills up in Palma and can be hard to get a seat on going to the Port.
If you are there in a Saturday go to the market and buy sobrasada and big loaves of bread. If you have a villa, there's a little shop close to the indoor market that does rotisserie chicken and other ready made meals (lasagne etc). You need to pre-reserve a chicken on a Saturday but other days you can just pop in in the morning.
There are loads of small supermarkets both in town and in the Port.