I'm going to get the XRCD version as soon as one pops up on eBay under 20 bucks. Of all the CD formats, I like XRCD best, HDCD next and then Redbook.
What? No SACD? Well, my CDT and DAC are older top of the line Wadia; and now sport a new Aural Symphonics glass digital IC between them. I've listened to SACD on my excellent system, but only on a multipurpose player. To be honest, it made me ill how good the SACDs sounded even on a crap player, but my Redbook equipment, even with standard CDs (non HDCD, nonXRCD) still outperformed the SACD by a little bit.
My conclusion: if you spend your money on great equipment first, you'll never miss SACD, not with three other formats available, two of them offering equally (IMO) incredible performance through good equipment.
BTW, I've discovered it's not necessary to have an "HDCD capable" DAC or player to enjoy the primary (upsampling) benefits of HDCD recordings if the decoding section uses dual chips or (as in the case of Wadia) special software.