My initial thought was 'does "photogeek" work for Jessops?' especially seeing as this is your first post on here.
If this is a serious question then of course you would notice the extra 100mm. It would make a huge difference. 100mm is a lot!
therefore 150mm is a lot!Versatile medium telephoto to telephoto zoom offers 35mm equivalent focal length range of 82.5–300mm
Equivalent 35mm-format focal length: 112.5-450 mm