These are excellent for the money, comfortable, the sizing is right, they're warm, waterproof, and do have a solid heel, toe and shin protection, which is more than you could ask for at this price. They do not provide a completely rigid ankle, which is important to stop your ankle rolling over if you have an accident at high speed as your foot may get twisted, trapped etc. However you'd normally only expect this from boots that cost well over £150. The ankle in these cheaper boots is at least partially rigid from all of the thick material, so would provde some resitance to the ankle rolling.
If I were riding into the city and on motorways daily, I would want my feet and ankles to be totally guarded, and therefore swallow the bill and pay £250 for a pair of Sidis etc. Nonetheless, for the 5 mile commute that I do and the odd ride into London, it's hard to look past these for £50.