Depends on what he's doing with it. The i3 is better for almost everything...except gaming, where the E-300 would be better (but note, neither can do high end gaming anyhow...)
If all else were equal (price, size, battery, brand) - I'd go with the i3 for sure.
thanks for that pov. Same brand and model but different spec (4gb memory for the E-300; 6gb for the i3) and the E-300 is £70 cheaper. He won't use it for gaming. Still i3?