In Germany you must have tyres suitable for the current weather conditions, regardless of the date. So if it suddenly snows in July those on summer tyres should stop driving immediately and park until conditions improve.
. Increasingly likely in spring and autumn.
This legislation prompted the rapid development and improvement of all season tyres, suitable for 130 mph on the autobahn in the summer,but also winter conditions typical of central europe. (In nordic countries etc ,proper winter tyres are adviseable, but these are unsuitable for summer) Incredibly Iceland has no legal requirement for winter tyres ,but in reality without them you would be in deep (erm) snow with your insurers.
This legistlation does not apply to the UK of course, and those of us who can pick and chose which weather to drive in might not need to rush to buy all season tyres.
But its the weather and road conditions that affects your ability to stop ,steer , or ineed get any traction at all.Not legislation. Personally I think anyone needing to replace their summer tyres would be daft not to consider all seasons.
I loved my Goodyear Vectors, Michelin crossclimates are well thought of , as are Vredsteins .
I have experience of much cheaper all seasons on another car. (Kumho Solus) They are more than adequate, but a bit 'squeally' when making tight turns on smooth tarmac (such as multi storey car parks) and I didnt think they climbed a steep muddy track quite as well as the Goodyears would have done ,although it was a different car. Summer tyres would have stood no chance ! On the plus side the Kumho are quiet, comfortable ride , wear well, and still perform at least as well in the summer as many budget brand summer tyres (and a few premium ones)