I did a lexus driving event just yesterday and felt exactly the same way.
They let us drive a IS 250 and 350 and a GS 450 around an autocross track, and do a lead-follow in the ISF and finally had us go passenger while a professional driver did a hotlap on California Speedway's infield track.

The power felt great. The handling was so-so. But in the end I didnt really feel that sportyness that I do from my S2K. A big part of it was just how quiet it was on the interior. I actually stalled the IS 250 cuz i couldnt hear the motor lol.