PERSONAL TRAVEL: my upcoming trip to Budapest and Vienna

For the week in between Christmas and New Year a friend and I are traveling to Budapest and Vienna.  Flights, Trains, and Hotels are all booked, except for the last night.  Here is our itinerary:

Monday: ARN-BUD with SAS nonstop, Art'Otel in Budapest

Tuesday: Railjet train BUD-VIE, splurged for the business class seat, 2 nights at Le Meridian Vienna hotel

Thursday: Railjet train VIE-BUD, no hotel booked yet

Friday:  BUD-ARN with SAS nonstop flight

I am quite happy with the trip, especially the two-nights in Vienna.  Do you have any tips about either city?  Please comment below, advice is welcome and will be followed.

Here is the breakdown of costs:

SAS Flights: 3000sek for both people (about 150usd each)

Railjet roundtrip:  308euro for both, roundtrip, biz

Art'Otel Budapest 60euro prepaid rate

Le Meridian Vienna:  10,000 Starpoints per night

The SPG Starwood points saved the day, as the hotel is pretty lux and would've been quite expensive.  We still need to book a place that last night in Budapest, have you stayed at a hotel you love there?  Please let me know.