A few years ago, NANOG had a discussion regarding various CWDM vendors. Repeatedly MRV was brought up as a good option for metro-area LAN type applications. There's been some discussions more recently, such as (coauthored by yours
On Mon, 30 Oct 2006, Deepak Jain wrote: truly): http://www.nanog.org/mtg-0606/pdf/lightning-talks/4-pilosov.pdf http://www.nanog.org/mtg-0610/presenter-pdfs/pilosov.pdf
Since then, I have actually touched some of the MRV product line personally and found it (and their customer support)... less than ideal. (not comparing to anyone else, and no one is really ideal).
The bigger problem was that the devices seem to be less than intuitive, but rock solid once they are working. (which is what everyone praised them for). Passive CWDM gear is pretty much all created equal as far as intuitiveness in how to connect it (assuming gear is non-broken). You have muxes, you have SFPs/GBICs, and you plug GBIC output into the mux input. :)
As far as the SFP/GBIC quality, I think MRV is very good. At one point, (maybe even still) Cisco OEM'd MRV gbics under their brand (and with attendant 1000% markup). You can also look at cubo and infineon optics, good quality at reasonable price. Be wary about chiwanese vendors - quality is questionable: high DOA rate, output light level and input sensitivity vary from one module to another. Pricewise, you might find that cubo isn't *that* much more expensive than chiwanese gear. Also, there's market (like, again, from yours truly) of the new-in-box MRV gear, which may also be an option.
We need to place a new order for some new fiber builds and were considering some other vendors. Especially in the nx2.5G and nx10G (are CWDM x-cievers even available in 10G yet?) range. Anyone have any new favorites? 2.5G are only slightly more expensive than 1G - if you have OC48 gear that is SFP-capable, by all means, use that.
10G CWDM is *rumoured* to exist, but I don't think there are any production ones yet. Feel free to correct me. 10G is all DWDM, and so far very pricy.