I have and I do , the GT3 Lotus is a blast, the MP4-12C is oddly quiet compared to the P1, the Alfa GTA is an odd but enjoyable drive, the Merc 190E is my favorite 'DTM', but I've only photographed the E30 M3.
I just enjoy the P1 more. McLaren designed it to be "the best driver's car on road & track", and in my opinion, they've succeeded and I eagerly await the possibility of seeing the P1 GTR in sim-racing.