One important thing about Mercure Gdynia: if you're booking a room for a stay during the summer months (not your case here, but the other forum members should know this), do NOT book anything of lower standard than the Privilege rooms (i.e. get Privilege, Executive or a suite). Standard and Superior rooms have no air conditioning and on sunny days become just terrible saunas. Otherwise, a very nice hotel, nice Winestone restaurant, and the fitness center has a standard 25-meter swimming pool. The location is just great: just opposite the theater and the funicular station, close to the main Świętojańska street (nice restaurants) and in walking distance from the port and beaches.

Other Accor hotels I've been in the area:

* Mercure Gdańsk Posejdon is the best Mercure around, it's even listed as a showcase for renovated Mercures in Accor promotional materials. Posejdon is located in a quiet area close to the border between Sopot and Gdańsk. Good place for a family holiday. Previously this used to be your typical Communist-era Orbis hotel, but now a very nice Mercure.

* Novotel Gdańsk Marina - almost at the border between Sopot and Gdańsk (you can walk to the Sopot pier through the beach in ca. 40 minutes). Hotel grounds have a tennis court and there's a swimming pool. No a/c (but somehow not as terrible as the non-a/c rooms in Mercure Gdynia), and the rooms are slightly worn out. This Novotel badly needs a renovation. I hope they do it, as this place has great potential. Novo2 is your standard Novotel restaurant with some local accents, pretty good (but Winestones in both Mercures above are IMHO better).