I posted this in chat as well but realised this might be a smarter place 
I have 2 identical laptops - 1 for each DS - they were brought with the sole intention of being able to play minecraft mostly (and a few other online games), watch videos etc, and as they were identical there are no rows over 1 laptop being slower than the other. Lag is a swearword in this house
1 broke (its only 9 months old) and was sent off to PC world to repair under their knowhow thingy - its been with them for 6 weeks - they have now written it off and offered me a replacement - the replacement voucher is for £50 less than the original laptop. All fine(ish)
However I cant find a laptop with the same spec as my original one for the price I have been offered. I appear to either need to downgrade to shared grahics as opposed to dedicated, have a slower processor, less RAM or harddrive or fork out an extra £150 to get something better!
The obvious dilemma with paying out more is that I dont want to smile, so which of the other options is going to affect minecraft / video watching quality the least?