Tandem Cycling - Sram XX cassette vs IRD Cassette

The new Sram XX 10sp cassette should be coming out soon, possibly next month. I know many people have had problems with the IRD cassette, and some who bought through Santana 10sp setup are content.
I plan on getting the Sram XX 11-32 cassette, and using XTR rear derailer and Sram chain on my Calfee.
Anyone else not happy with their IRD cassette looking into the new Sramm XX cassette as an alternative?
The quality control should definitely be better.

Jenson is supposed to get them in on September 18th. Since the SRAM XX cassette is over $300, I don't think I'll be looking to replace my 12-30 IRD cassette anytime soon.

We use the IRD 11-34 from time to time without any issues. It's a tad heavy, but the weight penalty is worth it on rides with climbing exceeding 12,000 feet.

Smaller chainrings or custom cassettes are much cheaper than the $300+ SRAM XX cassette.

We did have 26-39-53 cogs (with standard RD and brifters), but then I realized that a quad was possible and so I made it a 24-32-42-53 setup (and switched to a MTB RD and a bar-end shifter for the front). With a 12-26 10-speed cassette, we have all the low gears we need (we did a climb yesterday that was 1750m of ascent in 25km = 7% average for 15.5 miles), and we still have pretty tight spacing between all of the gears, front and rear. You wouldn't believe how much respect and intrigue we get from other cyclists when we show them our quad chainrings (we ride in the Alps - only the pro's and tourists use a standard double crankset here; triples and compacts are the norm).

Even so, the SRAM XX cassette could have its uses. I've been looking for a listing of the exact cog sizes that it uses and haven't found it anywhere, not even on the SRAM product page (http://www.sram.com/en/XX/products/cassette.php). The SRAM page does have a large image of the 11-36 cassette, which I counted the teeth on, and I believe it is:
11-12-14-16-18-21-24-28-32-36.
Companies often make different versions of their cassettes have as many cog sizes in common as possible to save machining/tooling costs, and I would therefore assume that the 11-32 has the same except for replacing the 36 tooth with a 13 tooth. However, this cassette is special becuase all of the cogs are milled from a solid piece of metal. I expect that tooling costs would therefore be the same regardless of cog sizes becuase none of the cogs can be shared between the two models. Even so, I wouldn't be surpised if the combination for the 11-32 XX cassette was:
11-12-13-14-16-18-21-24-28-32.
EDIT: Thanks to Andyman, here is the correct info: 11-12-14-16-18-20-22-25-28-32.

In either version, the 14-16 and 18-21 jumps would worry me as being a bit too much for my comfort, but this may be fine for some people. If we needed something with this kind of range, then I would build a custom 12-30 cassette that didn't have any large gaps between gears. I could easily build that for well under $300 and it would be suit us better, although it probably wouldn't shift quite as smoothly as the SRAM XX version or be quite as light.

Chris W,

Here is a description of the teeth by this merchant. There is no 13t or 21t on the 11-32.
http://www.competitivecyclist.com/mountain-bikes/product-components/2010-sram-xx-cassette-6375.452.1.html

Wow, thanks andyman. According to the Competitive Cyclist website, the actually cog sizes in the 11-32 are:
11-12-14-16-18-20-22-25-28-32
Which I think is an excellent choice of gears. They gave up the 13-tooth cog to get tighter spacing in the rest of the cassette. Great choice, way to go SRAM!

Now, if only they'd do something similar (i.e., give up the 13 for tighter spacing elsewhere) with their 11-28 cassette then I might start using that.

In about one more year, there will be a third choice of a wide-range 10-speed production cassette. Apparently, there are strong rumours that Shimano XTR will be going 10-speed for the 2011 product season, read more here (http://www.bikeradar.com/news/article/shimano-xtr-to-get-10-speed-cassette-for-2011-23307).

Jenson is supposed to get them in on September 18th. Since the SRAM XX cassette is over $300, I don't think I'll be looking to replace my 12-30 IRD cassette anytime soon.

Maybe they should have called it SRAM $$$