Hi,
I think if you are on a packaged tour and don't expect to walk around on your own, the the Hyatt Regency is a real good place. It's comparatively one of the newer hotels in Kathmandu, and the outdoors are nice.
They've got some good restaurants, and food is good. The Rox bar is one of the more happenning places in town, specially on Fridays.
But, if you like to explore the town, go shopping, go to Thamel (the touristy hotspot), or want to eat outside in some of the best restaurants in town, then Hyatt is a no. There is simply nothing outside the hotel gates. You need a cab to get anywhere.
Additionally, it's much better now after road widening, but the road that runs between the Hyatt and the city when it hits the ring-road is a major choke point and at rush hour best be avoided.
Many of their senior staffs are very experienced people, but the downturn in the last few years had meant that there was cost-cutting and the better trained junior staff left mostly for the hotels in the Middle East, and the newly hired in-experiences showed, but with the up-turn, hopefully things get better.
I have had my friends stay at the Soaltee (now crown plaza, previoulsy oberoi), RAdisson, Yak and Yeti, Hyatt, Dwarika and the Annapurna (when it was still Taj Annapurna). I have stayed at all except the Anna (though u can imagine that i have a house to stay when in ktm).