S&B PM11 3-12x50 Question

[dawncapel]

Hi
I see that the cheapest of the S&B 3-12x50 PM11 scopes, which retail around £2k has no parallax adjustment. Reading the specs S&B say parallax is fixed at 300m. What is the designed use of this scope without a parallax adjustment? Can it be used for target shooting from 100 yards to 800 yards. Would the lack of parallax make it difficult to gauge performance of home loads? Is this a good scope for stalking, target shooting? Any and all advice welcome.