I think both are great speakers. I owned Proac 2.5s and Thiel 22's, not the newer 2.3's. Although the Proacs are very musical and smooth and non fatiguing, I found that the presentation of vocals to be a bit laid back. It was as if the voices were too deep into the soundstage for my preference. I like them to be closer to 3rd row Vs where they seemed to be in 10 or 15th row. This is one of the reasons I sold them for a pair of B&W N805's, a much smaller speaker that does not play as loud and does not project such a large soundstage. They do have a sweet top end and the vocals are more forward. I think the Thiels are more forward as well so careful component matching is critical as always.