People will always vote in favor of a custom remap to your car, which I am sure are better overall.
I went with a dtuk tuning box as it has a number of different remaps built in and I liked the idea of being able to take it off when i want and sell it after i sell the car.
Be warned though I have purchased tuning boxes for £120 and they where awful. Paid £320 for my dtuk, had it a few years now, no issues, and noticed instant differences the moment i first gently accelerated in 3rd gear. Move have advantages, but has said, most will go with a custom remap and rolling road before and after.