Never had a problem with these, after having one major problem that needed 7hrs of drilling out.
Six sided socket, long long bar, LOTS of heat into the bolt, LOTS of Plusgas, PATIENCE, moving it a bit, then more heat, the more soaking. They will always come out if done patiently and slowly.
Heat should not really be applied to the strut though, but with a very small flame/torch you can get it just on the right parts of the bolt.
Heat cycles combined with penetrating fluid with time to soak... never failed me yet.
However, Im never in a rush to to these, (avoiding another 7hr drillout) so if one is really really bad and has never been moved from factory, rather than take a risk im happy to do it over a few cups of tea and take up to 1hr for a bolt if it avoids more pain down the road
