I installed a KR1 (Dlink ODM) a few months ago for an camp in mid-Missouri. They are using a Sprint S720 EVDO Rev. A Card as the wlan nic. Overall the KR1 works well. The only major issue the camp has had is signal strength now that the trees are full -- expected considering there's no visible towers anywhere on the horizon. I since had to install a YX500-PCS booster.
A few notes about my experience with this router:
- A firmware update was required for additional device support such as U720.
- It has open source (GNU) firmware/OS. (I would probably brick it if I didn't already give it away or could afford another one)
- the 802.11 radio will interfere with the CDMA radio at low signal levels.
- The flash interface is SLOW -- take your time with firmware. I suspect this is like some DLink wireless routers and has a slower serial flash interface.
- You'll have to apply connection card updates using Sprint (or whomever's) utility. That means you may not get a connection or proper speed until you update the PRL and Firmware on the card.
Bottom line, If you're looking for a SOHO or mobile solution the KR1 is a good device. Given its relatively limited adoption and target market it seems Kyocera did a fine job of engineering a device that get's the job done for a fair price (they even throw in a 12 volt vehicle adapter to sweeten the deal). However, if I had to make this purchase today, I would take a serious look at the Linksys WRT54G3G or go with Kyocera's new model the KR2.
Amazon Links:

Kyocera KR1 Mobile Router - Wireless router + 4-port switch - EN, Fast EN, 802.11b, 802.11g: Electronics
Linksys Wireless-G Router for Sprint Mobile Broadband WRT54G3G - Wireless router + 4-port switch - EN, Fast EN, 802.11b, 802.11g: Electronics
Kyocera KR2 EVDO Mobile Wireless Router: Electronics
Wireless Extenders Cell Phone Signal Booster - 1900 MHz YX500-PCS: Cell Phones & Service