I haven’t heard the 34 string Rees harp, but two of my students (sisters) recently bought 30 string harps from Rees. I thought the sound was warm, full, and beautiful. They seemed to get good volume for their size. And the overall quality seemed really good to me. I haven’t spent a lot of time with these harps, but I was impressed by them. I would definitely consider buying one, if in the market for a smaller harp.
I know it’s not the harp you specifically asked about but since they are similar, and by the same maker, I hope it is helpful.