We stayed four nights in Janis appartment and I can only recommend it. It's very comfortable, new and clean. We liked the location on the other side of the river as it was an easy morning stroll across the bridge to the old city (or take the bus or tram which ride nearby). The flat is equipped with everything you may need - especially we liked the very modern bathroom.
We did some of the suggestions in Janis guide book (e.g. restaurant La Fazenda for dinner and the Saturday market) and liked them a lot.
Janis answered all our requests really quick and nice.
We had wonderful weather which even allowed us to go swimming in the Baltic Sea, but even without Riga is a perfect spot for a weekend trip. We will certainly come back and hope we can stay with Janis again.