I had originally thought that the big difference between the 2012 and 2013 303 Firecrest Clincher models was that the SRAM/Shimano cassette compatability was 10 versus 11-speeds respectively. However, it seems, when looking at online shops, that some of the 2012 models are billed as 11-speed compatible. Also, the 2013 is a 23 grams lighter.....insignificant, yet I wonder why?

Does anyone know if I am wrong with what I seem to be seeing on the various sites?

the 2013 has a new hub design.

2013 also has a higher spoke count

2013 is the same spoke count as Zipp has been for ages - 18h front, 24h rear.

These small incremental changes and what are hopefully improvements are welcome, but it is getting almost as bad as computer and mobile phone manufacturers. This brings to mind Adobe's and Window's incessant and constant "upgrades," but at least those are sent out free to all people that have bought the products.

Well, they put a lot of time and money into the current design, and it is still top notch. So they need to recoup money until they can come up with something significantly better to make the investment in molds that make financial sense.

I welcome hub redisgn and improvements. I just dont get the whole micro adjustment for the hubs/ wheels. My rear hub rim has play back and forth even tightening it up past recommended tension. Albeit just slight, still makes me wonder why????. Bearing and hub play should be somethng not allowed IMO in a hub.

Im just waiting for my rear hub to die so I can have them strung up better hubs. Rims are fantastic, rear hub is just suspect IMHO.

zipp hubs are pretty darn great. any honest wheelbuilder will confess this to be true.

there is a great deal written about ply in zipp hubs (when unloaded) -- it's intentional and part of their design philosophy. a quick google search should turn up some good reading. you may disagree with them, but it's done for a reason.

pretty darn great? Really?!
I don't see too many people getting wheels built up with 188 hubs? Is there a reason why they don't, and choose CK, Alchemy, WI, or DTS hubs instead?

Because in many markets the Zipp hubs are not for sale seperately. If they were, and the price was reasonable. I have no doubt they would sell

The lack of use of Zipp hubs aftermarket, in my mind is probably more related to these things than quality:
1. price is high
2. you are stuck with straight pull spokes, which isn't a huge thing but limits you pretty much to CX Rays
3. front hub doesn't have a 20 hole option
4. rear doesn't have a 28 hole option

I agree with Tetonrider, they are nice hubs at a good weight. Maybe not the best and maybe require a little more care but when you consider the company they are with they are expecially good: they stack up well to Mavic but are lighter, and are better than Hed. Enve doesn't make hubs.

Very few (performance) wheel companies that are big in the market are making their own hubs or making them as well as Zipp.