We were three friends "climbing" this mountain after spending more than three weeks trekking Jiri - Namche - Gokyo (Gokyo Ri) - Cho La (easy pass) - Gorak Shep - Kala Pattar - Dingboche - Chukung. Well acclimatized we spent one night in Island Peak Base Camp (5100 m) and the next in a high camp at about 5500 m. We started from high camp about 04 and reached the glacier at 07 (about 5900 m). We had a climbingguide which proved very useful to show us the way in the darkness for the first two hours, although this part has a more or less defined path. Reaching the glacier we put on crampons and shifted for an ice-axe instead of a walking stick.
On the glacier we did not not see any crevasses at all, and did not use rope, but we followed the tracks on the glacier. Four weeks before we climbed the mountain heavy snowfall had probably covered all the crevasses. This part between 5900 and 6050 m was just easy walking on relatively flat terrain.
The steepest part is the wall from about 6050 to 6150 m and is approximately 45 degrees steep snowslope (maybe ice at times). Our guide put up our 100 meters of rope and we jumared alle the way to the summit ridge. In the absolutely perfect conditions we met I do not think this was necessary. Anyway we used the rope for extra help up to the summit ridge.
The summit ridge was much wider than I expected, so the last 100 meters along the ridge was no more than a walkup without ropes, but of course we used ice-axe and crampons. I have heared about crevasses along this ridge, but the snowfall one month before had probably covered everything. We were quite slow and reached the summit at 11, as the last team that day. The view from the summit was fantastic, but you feel small under the colossal south face of Lhotse which also hides Everest.
The physical challenge of reaching the summit of Imja Tse is in my opinion greater than the technical challenge. You need an ice-axe, crampons, harness, rope and a lot of stamina.
To this it should be added that the heavy snowfall four weeks before we climbed the mountain had made the snow on Imja Tse perfect for climbing. It was also blue sky and almost no wind the whole summitday. Do not underestimate this mountain if conditions are worse than we experienced.
We had a trekking company in Nepal which did a good job arranging with guide, climbing-guide, porters and cook for the whole 30 days trekking-expedition.