cumulus experience
"whilst in that cloud , it was incredibly bumpy and I was struggling to maintain my altitude clibimg 200 feet and then descending 200 feet in a few seconds or so. Felt like a fairground ride. I thought that I had perhaps bitten off more than I could chew and after a while requested a descent to become VMC. Quite frightening at the time but glad I did it."
Spike, this was a cumulus cloud. Penetrating cumulus clouds can make you feel like the wings are going to snap off. Reduce speed to Va, pop the gear down if necesary to increase inertia and hang on. Being chucked around whilst in IMC is a worrying feeling, particularly at night. CBs also have the added rain factor and heavy rain associated with them can also be disconcerting, best to let George the autopilot fly and try to avoid banging your head on the cockpit roof. I never set out to fly through a CB, when you are IMC in an airway embeddeds can find you, especially around active frontal systems. I would agree with IO that above is better - in his scenario I would be at FL200 with O2 on watching the ice melt in the sunshine. Or even better reschedule the flight to avoid the muck completely and have an easy ride.
Stratus are smoother affairs altogether, slow insidious icing can occur and vis beneath can be awful but they are steady eddies.
I'd far rather have 1000 miles in stratus than 5 in cumulonimbus.
Incidentally - a little bird told me that WX:XM weather will be available soon in Europe. This will help with CB avoidance far more so than the stormscope.
SB