Did it with my dad in 91, we camped at the endmoraine of the glacier
Ascended Stor- and Lillesylen in Easter 2003. Went with skies to below Lillesylen. From there we walked up. Very nice cornices along the ridge til Storsylen. Wetaher was awesome. We sat in T-shirts on the peak!
I have climbed it the normal route / via Lillsylen / from Norway and done the traverse.
We climbed the real start of Stora Traverse over the pinnacles of Templet, but having started way too late (around 2 pm) we only made to the top of Templet (hardest part of the route, not counting the 20 odd meter slab to the summit of Stor Sylen).
The weather was alpine like changing from sunshine to hailstorm and snow blizzard.
Most of the climb was basically an exposed scramble witha couple of short under 30 feet boulder problems in between.
The time for this climb was not that good, as large quantity of this route is a bit loose and it wasn't cold enough to freeze the loose bits, so the climbing was exciting.
The partly snow/ice covered rock made things also interesting.
None the rest a nice afternoon climb ended with a big cup of Coffee at the Fjällstation, followed by boring uphill slog to the tent.
We reached the Summits of Lill and Stor Sylen without any bigger problems, though the weather turned a bit nasty and made routefinding a bit difficult.
The whiteout was also quite good, as my less experienced friend was scrambling much easier as the exposure at the ridge didn't seem that bad ('cause you couldn't see how huge the drop was).
The nasty weather was a freak snow blizzards, that covered the ground with about 2 inch of snow (not usual this time of the year to have that much snow, if any).
Also the slabs near the western end of Slottsdalen were really slippery and the weather as the rest of the ground was pretty moist.