Marcus' studio was a great place to stay. It is very close to the city centre, very easy to get to from the train station (3 stops on the 3 bus and a short, flat walk, or one stop via M2 metro to Lausanne-Flon, up the elevator, and then a longer-but-flat walk). The studio itself is small, but the futon was comfortable, there is a small fridge, microwave, coffee maker, hot water kettle, and a two-burner stove if you want to cook your own food. The balcony has great views of the French Alps, the Pont Chauderon, and you can see le Léman. Street parking is available, but it's one-hour or residential only from 0900-1900, which is fine if you're going to be gone all day.
Marcus is an absolutely fantastic host. I can not recommend him enough. He was very responsive to all of our messages, and went out of his way to make sure that everything was great for us, and was very prompt being where he said he would be to check in and out and helping us with our own stupidity.