We were staying in Hotel Piazza Ascona for a wedding's weekend and for this purpose, it was truly wonderful. The entire "house of olive" (casa della olive) was booked by the wedding company and it was never complicated to arrange things during day therefore. Nevertheless, there were some points:
+ super nice location. right at the lakeside diminishes your travel time to zero. there are lots of restaurant and some bars around, makes it easy to enjoy dolce far niente.
+ breakfast buffet is nice, something for everybody. you can enjoy the buffet from 7.30 till 10a.m. and they do not close the buffet right at 10.01a.m. and let you eat for another 30ish minutes (maybe they dont let you in after 10).
+ had a spacious room for luggage
+ good roomservice imo
+ having meals in the hotel's restaurant will be rewarded with 10% discount on the price
+ although there is no street going to the hotel, you can temporarily drive to the hotel for unload the luggage etc
+ the garage is only 15 bucks per day
+ reception is very friendly and helpful. they also speak german fluently and surely english
- there was no air-conditioning in the room. we tried to keep windows open during day, but without success. also, I stayed on the ground floor, keeping the front window open is a bad idea and the very small bathroom window was simply not enough useful for bringing the temperatures a bit down. same for the bathroom
- obviously, there is a wifi-password, but I never found a note for the pw read more