I messed around with XNA at first also, but was a a few years ago. My teams been using Unity lately. It's got its limits, but overall I've really enjoyed working with it. ..though, this is from the point of view of content creation.
There are some great tools for Unity3D which can aid you in your 2D workflow. I just found ex2D on sale in the asset store for $15 bucks and it looks to be worth every penny. (Not affiliated with them ) Couple that with the current Unity license promotion and you have an inexpensive, yet powerful, 2D platform with the versatility of 3D.