Is 2 nights enough time for Riga
Opinion of Rixwell Irina Hotel or Ibis Riga Center
3* hotels same area.
Thank you
I don't know either hotel at all, but I see their locations on a map. That's a great area - close to the bus/train station, near the central market and the old town. For some reason, hotels were pricey when I visited in May 2016 so I picked a place someone had recommended further out near the Art Nouveau district (glad to be close to that though, those Art Nouveau in Riga are amazing!). Riga is pretty big with large blocks, but I didn't have trouble getting around but bus and tram (and a lot of walking). You may not need the bus where you are staying except possibly for that long walk out to the Art Nouveau district, but if you do it once and back it's an easy walk.
If you want to do any day trips outside of Riga, being near the train station is handy. Be careful about pickpockets - I was targeted while carrying luggage in a very brazen attempt near the station there and nearly lost my wallet and passport, on the steps near the station where it wasn't busy at all. Riga feels so safe that it's easy to let your guard down.
FYI, a 3-star hotel in Europe means something very different than in say North America. The number of stars means only the types of amenities it has. It could be a 1-star or 2-star hotel and be lovely and charming, or it could be a 4-star hotel but be a dump. Can't imagine an Ibis would be awful, but I'd would read the Trip Advisor reviews anyway.