Between Iphone 4s and 5 or 5c?

Hi, I'm from India, and IIm a user of Android, currently I'm using Samsung Galaxy 3 I9300. Though it has a quad core processor and 1 gb RAM but the phone really lags a lot, I asked many for this and they suggested me to go for IOS, as it is lag free and very much flexible, now I want to shift from android eco system to IOS, I want to know in terms of performance is Iphone 4s is really much behind than IPhone 5, as one has 512 mb ram and one has 1gb, and with android it matters a lot, but I have no idea with IOS, so IIm very much confused for this, as in India there's a huge price difference between Iphone 4s and Iphone 5, and If I ll go for Iphone 4s can I run multiple application without lag, because with my galaxy s3 it lags and is IOS really lag free. Please, Iphone users provide your honest suggestions.

Even on 256 mb ram iphone 3gs… You can multitask and it doesn't lag at all then you can be asured of 4s. Don think twice as it has 512 mb ram… Its ios. Ucan rely on it… Ios doesn't use much ram… 4s is best if its in your budget. Go for it