Am wanting to upgrade my 4yo Macbook but totally unsure what to get!! My one has 2gb RAM and 320HD and 2Ghz and does lag at times. HD often hits 300GB used but I do need to clear up some pics. Main uses (aside from mail and web) is Lightroom and iMovie. Dont use Adobe PS yet but may well do in future. I am confused by chips - something like a 2.9 dual core i5 compared to a 2.4 quad core i7... what is the difference? Is a slower quad core better than a faster dual? Budget wise I am flexible, ideally want to keep cost around £1500 but if I have to spend more I will. So, is the better graphics in the 15" that much better and useful for what I do? I am torn between retina and non retina. Screen is nice but the big thing for me is the size and weight of the retina (plus in the store, the screen 'wobbled' more on non retina). Would I be better off with say a 750mb or even a 1gb HD or going for a smaller SSD and using Time Capsule as a storage place for stuff like music or film footage? Tempted by a refurb, some just have a price, others have a saving added, does that mean anything? Also, is it likely to be marked or have scratches? Are they ex store machines? I am also considering holding off until a new one is launched as I dont NEED one yet (but will at some point this year). Maybe the newer one will have the ac wifi, better battery life, cheaper ssd and the option of 16gb on a 13"? At the moment I think the ones i favour are: non retina 13" 2.9 i7 with 8gb RAM and 750 HD for £1249 retina 13" with 2.5 i5 with 256/512 SSD at £1409 or £1569 retina 13" with 2.6 i5 with 512 SSD at £1689 or possibly retina 15" 2.4 i7 quad for £1799 (8gn ram & 256 SSD) So, any ideas and tips to the above? I would like this to last a few years, and maybe in a year or 2 I may upgrade camera to a Nikon D800 (typical files approx. 36mb+ as opposed to my current 10-12mb size).