We (a couple) stayed at the hotel during october and found the hotel to be satisfactory. The Check-inn was easy and we were able to leave our bags at the hotel as we arrived in Vienna early in the morning.
The location of the hotel is quite good, as it is very close (5 minutes) to a subway station and one is also able to go by foot to the city centre.

We did not eat breakfast there, thus I am not able to comment on it and did not have any contact with the staff - other than at check-in/out. The room was basic and clean.

I would recommend it for business trips or city visits where the time in the hotel is minimal, as it did not feel "homely".

We stayed one night in this hotel during our stay in Vienna. Hotel is situated in small and quiet street so we had no problem with sleeping. Check-inn was prety quick - for our group it took only 5 minutes. People working there were ready to help us in any way. Rooms were spacious and clean but not ultramodern. Breakfast was very nice - lots of choices for everyone.
We came by our own bus but if one need to get to city center it can go one station by bus to get to the U1 underground station (Vorgartenstrasse) which is 5 stations from Stephansplats station (city center).
This is hotel for people who want to see Vienna but are on middle size budget and are willing to use city transportation to move around city

The location of this hotel is 5 minutes walking or 1 stop by bus from U-Bahn . Then after 10 minutes you reach Stefansplatz. Rooms are spacious, clean, design like many other city hotels - not impressive. Staff and service professional, good choice for breakfast but breakfast room crowded. I stayed 2 nights for a business meeting.

The only reason we stayed at Hotel Lassalle was because it had been booked for us by the company that organized our cycling trip through Austria. It was located 4-5 subway stops away from the center of Vienna in a not so nice area. The closest U-Bahn stop was "Vorgartenstrasse" which was about a 15 minute walk to the hotel. I definitely would not do this walk alone at night.

Anyways, the Hotel Lassalle is part of the budget Austria Trend hotel chain and was consequently very predictable in terms of decor and amenities. Guests have 2 choices when it comes to rooms: rooms facing the front noisy street or rooms facing the backyard which has been turned into a giant playground for local children, thus it was very loud in the late afternoon/early evening. Given that Hotel Lassalle has no air conditioning, in order to get fresh air, we had no choice but to open the windows and consequently put up with a lot of noise.

Our room came with a minibar and wifi/internet was free although the signal was very weak and kept disconnecting.

The brightest spot of our stay at Hotel Lasselle was their enormous complimentary breakfast buffet which featured the usual breakfast dishes as well as a variety of salads, cheeses and specialty waters.