For Swiss (expensive) standards, this middle class hotel offers very good value for your money. The hotel has been owned by the same family for a few generations, and you notice this in the atmosphere. It is an "old" hotel, charming and in good shape as well as very clean, but lacks some modern facilities like an elevator (they will bring your luggage to your room). They do have a sauna and a whirl-pool, however (which I did not use, so cannot comment). In general, there are a lot of small pleasant details that will improve your stay, e.g. a good offer of newspapers to read (however mostly in German).
They do not have free parking (few hotels in Pontresina have - it's much better to come by train anyway).
The service is very friendly and personal. E.g., they will fetch you from/bring you to the train station if you ask them in advance - unusual for a middle-class hotel in Europe. Information at the reception is very helpful. The only person who slightly got on my nerves was the lady serving breakfast who several times talked loudly to other guests about her family and other affairs - but perhaps these guests exactly appreciated this kind of conversation, who knows. The breakfast room is nice, though it is a bit of a nuisance that you always have to stay at the same table (which you do not choose). Breakfast itself, for a middle class hotel, was excellent, apart from the coffee that was still ok. You can have dinner (menu) in the same room if you book half-board. For those guests who do not, they offer dinner in another room which was nice yet I felt a bit deserted there during my stay (food was simple but fine). There are however quite a few restaurants nearby, so no problem.
They seem to have two types of rooms: in the newer "basement" wing (with windows and access to some out-door terrace) they are larger, with (again for Swiss standards) big bathrooms (with a bath tub, two sinks, etc.). These rooms also offer a lot of cupboard space but are a little bit less charming, though far from sterile. In the upper floors you have the "old" rooms which have beautiful wood-covered walls that give a very cosy touch, but (at least the one I had) may be a bit small for couples and have a much smaller bath-room (only a shower). These rooms also have a balcony; unfortunately, it was much too cold in January for me to use mine - in summer they should be great. It should be noted that the "Hotel Post" is one of those hotels in Pontresina (most of the others are more up-market) that have free mountain views. On arrival, I was given (as a single traveller) one of the "modern" rooms but managed to change to an old one on my second night as it suited my tastes better. It was no problem to change rooms even though they were practically booked out, and in the end they gave me, without my asking, a smaller price than I had reserved since the room was smaller - a gesture I appreciated.
By the way, both rooms were very quiet even though the hotel is just next to the main street - the rooms are oriented towards the other side. For those who really like it quiet, I would recommend to ask not a room on the first floor as you might be able to hear the restaurant from there. Finally, they have simple but pleasant rooms on the ground floor to read, play cards etc, so it could also be good choice for bigger groups of people. To sum it up, I really enjoyed my stay and thought they did a great job. Yes, there are better - particularly more elegant - hotels in Pontresina, but then you pay (much) more for them.
A few words on Pontresina for those who do not know it: the "Oberengadin" valley has a breathtakingly beautiful landscape, for me one of the most striking in the whole Alps. It is suitable for downhill skiing (though you need to take a public bus to get to the various slopes), cross-country skiing and hiking. There really are lots of things to do, plus some really top-notch hotels. On the negative side, this has lead to not only big groups of tourists, but also to too much construction (in particular around St. Moritz and Celerina). Pontresina is, together with Sils, one of the villages that has managed to restrict construction to a more or less reasonable level - however, it has not been spared. If you want to discover a more "authentic" part of the Engadin valley, take the train (about an hour) to the "Unterengadin", where there are some truly beautiful villages left (Lavin, Ardez, Guarda, Tschlin) which have a very special architectural style.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.