I believe that Cho Oyu is in better shape in the post-monsoon than pre-monsoon. Hillary turned back at the ice cliff pre-monsoon 1952, but it was first climbed post-monsoon 1954. There was a lot more snow on the mountain in post-monsoon 1954, judging from the photographs in Tichy's book, Cho Oyu: By Favour of the Gods. On the other hand an international women's expedition was hit by an avalanche in 1959. For a while, Cho Oyu was known as "Lady Killer Peak."
If I go back to Cho Oyu, I would bring along my 2.5 lb Chouinard Piolet, a pair of rigid crampons, and go in the post-monsoon season. And I would also approach it by truck from the north, simply because I have never been there before!
I joined a commercial expedition to Nepal over April and May to climb Cho Oyu (26,906'). We flew to Lukla from Kathmandu, and approached the mountain from the south via the Lunaq Valley. We established our base camp on April 21 at 17,100' along the Nangpa Glacier, about 4< miles south of the Nangpa La. We then crossed the Nangpa La (18,753'; technically speaking, we were in Tibet north of this pass), and climbed the classic west ridge route on the mountain. We established Camps 1, 2, and 3 at 19,000', 20,200', and 22,500' on April 25, April 28, and May 3. Camp 3 was damaged by high winds on May 5, with the loss of four man-days of food. This, combined with the apparent theft of ten man-days of food from Camp 2 on May 1 or 2, put a major strain on our high altitude resources. (For the record, the suspects were either the IMC or DAV Summit Club expeditions.)
Camp 3 was reestablished on May 6, and Camp 4 (in reality, a bivouac with a tent and stove, but no sleeping bags) was placed at 24,000' on May 7. The next day, our leader Mal Duff (Scotland), Dave Horrex (England), Josi Delgado (Venezuela), Clive Jones (New Zealand) and Pasang Gombu Sherpa (Nepal) reached the summit. This party returned to Camp 4 in deteriorating weather that night, and sometime during this period, Clive frostbit the toes on his right foot.
On May 8 Neil Lindsey (England), Rick Nowack (a fellow Californian!) and I set out from Camp 2 with our sleeping bags (but scant other supplies) for our summit bid. Above Camp 2 the route followed the crest of the west ridge, with some fixed ropes, to the base of the 300' ice cliff at just below the 22,000' level. There was a dearth of snow on the mountain this season, and this cliff consisted of hard, dense blue ice. My highly skilled friends told me that it was only Scottish 2, and they casually front-pointed it with their semi-full expedition packs, as if they were spending a winter afternoon at Lundy Canyon (but the frozen waterfall ice of the Eastern Sierra is a lot softer than this stuff). I couldn't get anything to stick, except for the ascender on the fixed rope, of course. Cutting steps was impossible, and there was no spare rope available for Neil or Rick to give me an upper belay. After two hours I managed to drop a mitten and only climb two-thirds of the way up the cliff in rapidly worsening weather. I was in over my head and I returned to Camp 2. Our Sherpas there were glad to see me (they attempted to dissuade us from making our attempt that morning, due to the lack of food). I offered them a bonus to lead me up the ice cliff the next day, and our sirdar, Chwang, wisely replied: "Death is up there, life is down here, and we can't eat money anywhere."
Everyone returned to either Camp 2 or 1 the next day, and I dined on sunscreen at Camp 2 that night. Clive's frozen toes were grey, blue, purple and swollen, and he and I swapped our right boots so he could hike out; he could only wear my size 11 Jannus without the liners! We were all back at base camp by May 11, and by Friday the 13th we all assured Clive that his toes looked a lot better. And on that ominous date we began our return to that other world.
The other expedition members were Englishmen Geoff Pierce, David Holl, and Joe Simpson. Yes, that's right, Joe Simpson the author of Touching the Void, The Water People, and the forthcoming This Game of Ghosts. (Nick Clinch once said that name dropping is a sure sign of lack of achievement.) But, seriously, this was a great trip, with highly skilled, yet personable climbers (I sometimes felt I was on an SPS trip), and I am glad that I went. And it was the best organized commercial expedition that I have ever been on.