Of all of the Buda hotels, probably one of the best situated. You will be able to walk across the famous Chain Bridge to reach Pest, but the walk will be right at your 800m then ....... But! Right on the Pest side is the Sofitel Hotel, and in front is this beautiful little outdoor café with a wonderful view. So sit and take it in.
To get to Market, Jewish Quarter and the base of Andrassy ut, let me suggest you take the 19/41 Tram to the Gellert Hotel. It is about a 10 minute trip with about 200m of walking. Then from the Gellert you get on the 47/49 Tram to cross the bridge into Pest. First stop is the Great Market Hall, Third Stop and a short walk is the Great Synagogue, last stop takes you to Deak Ferenc ter and very near the bottom of Andrassy ut. From that point with a short walk you can get on the M1 for the Opera, House of Terror, Hero's Square, City Park, and Szechenyi Bath.
If from your hotel you get on the tram heading in the opposite direction you will end up at the always fun to try and pronounce Batthyány tér From that point you can take the M2 Metro line over to Deak Ferenc ter in Pest and then on to the Keleti Station. Also from Batthyány tér the H5 Commuter train goes to Szentendre. If you take the H5 just one stop you will find yourself at the bridge that connects Margret Island to Buda and Pest. The 4/6 Tram stop is also at that location and with the 4/6 Tram you can cross the river and get to the midpoint of Andrassy ut, The New York Palace Café and just in general see an interesting part of Budapest. It also goes in the other direction to very near the Castle District.