I've stayed at the La Perla twice during my time in Ascona. It is located on a lovely site with lots of flowers and a view of the lake. The rooms are extremely clean and very comfortable. Many have a small terrace. Every interplay with employees has been a true joy, esp. Lisa. All are very kind and willing to help with any situation. I have no hesitation recommending this sweet European hotel to anyone at any time.

We stayed here for just one night, and it was perfectly fine. Positives:
-beautiful view of mountains from our balcony
-clean
-friendly staff
-good selection for breakfast

The only negative is that things got a bit noisy in the morning, so I wasn't able to sleep in as I'm a light sleeper.

I stayed there with my partner on half-board for 3 nights.
The room was very nice - in classic style, well equipped and with very comfortable and wide bed. Everything was clean and I think it had to be renovated not a long time ago. Everything worked in a bathroom, enough towels. We were there when raining and room was very cosy as the proper heating was on. There was a filled fridge, TV and wifi available there. A nice size balcony with chairs and table and lake view over the Ascone roofs, with mountains behind. Very nice. Parking available for 7CHF/day.
As we had a half-board, we tried the restaurant services, too and met all the other guests. We were one of the youngest ones as the hotel seems to be very popular by a retired guests, we felt a little bit funny:-) Service was not that comfortable as the waitresses didn´t speak either English or French or proper German. I know we are in Italian part of Switzerland but at the 3star hotel restaurant I kind of expect that the staff will be better language equipped (on the other hand, all the receptionists we spoke to spoke several languages). The athmosphere during the meals was pleasant and reminding organized trips:-) If the weather would allow, there was a nice terrasse to enjoy the meal, too.
Breakfast was average, no croissant for us late birds, cheapest kind of salami, good cheese. Only black tea available or coffee, cold milk, cheap kind of juice. Nice espresso with hot milk on request. Bread was always fresh and several options to choose from.
We had to take a set menu for our dinners, it was always nice and tasteful, not extremely big portions. If we would have to choose from the carte of the restaurant, there really was not a bigger choice.
Be carreful when looking for the hotel as they changed the name of the street to Strada de la Collina...

Stayed here for a week for business at Monte Verita. It is a short walk from Monte Verita (1 km away uphill, only take about 10 mins), and just a few minutes downhill to ascona. I was staying in the section called Villa Favorita, which was a disappointment. I had a small room (single bed) with basic facilities. The toilet/sink/shower more or less overlap in the small bathroom, and there was just soap and a sachet of shampoo provided, so dont forget to take your toiletaries. The shower was good - good pressure, height and temp. adjustable. There was one socket available in the room (a plastic plate with lots of small holes) which took my euro-uk plug adapter fine. There was one lumpy pillow and a duvet, but it was warm enough. There was a hairdryer, although a colleague in another room did not have one or get one when she requested it from the desk. There was a view of the road from the window, and the shutters did not close (I think the wood had warped) which meant they banged all night in the heavy wind. The room was quite noisy because you could hear all the noise from the room above as well. There is no alarm clock. I guess the room had been recently refurbed because of the paint on the carpet. The door lock did not look very secure compared to other hotels I have stayed in, but I assume it has a low crime rate there, I certainly had no problems. There was a hanging rail and hangers which was good. It was 3* clean - I mean a bit of dust and the odd hair from the previous occupant. Some other colleagues had good size, lake-view rooms, so I guess your experience depends on where you are. Breakfast was fine, although a bit of a trek (outside, along the bridge to the main building and down 3 flights of steps), there were boiled eggs, bread, toaster, cheeses, fresh fruit, yoghurt, meat slices, croissants/pastries and cereals. Once they brought me a cold pot of tea, which I could not resolve because of my mediocre knowledge of italian, but generally breakfast was very nice. It was not too busy when I was there, but we had early starts (7am). I was not able to get wireless internet access in the villa favorita. Overall, although it was fine for my business needs, I would not choose to stay here again because I found it far too noisy.