Sennheiser RS 170? Is there any competition? I've been trying to decide between HD 598, RS 180, RS 170 and ATH-M50.. I have some use for closed wireless headphones (Vacuuming etc. I have previously survived with Sansa Clip and Sennheiser CX 400-II’s, but it’s too much hassle), but I think that for “serious” listening I’d prefer open headphones, so I have come to conclusion that I just can’t make it with only one headphones. RS 170 (if no better ones exists, for a reasonable price) and HD 598 it is.