Are remaps worth it?

[Golaboots]

I go from an enforced company car, to cash for car shortly and the scheme is somewhat less than generous, imposing a strict 4 year age limit on the car.

I don't want to put loads of my own money into chugging around for work but don't want to chug around too slowly.

I was wondering if a remap, or tuning box can help out. Would people expect them to give a horrible slow 1.6D the relative performance of a 2 litre but for less than buying/leasing the highr output car?

How do they affect insurance?

[Golaboots]

Thanks for the replies.

It's all speculative at the moment. I've been driving around in a 1.6 diesel focus as a short term lease and know that I can't do that for the next 90k miles. Too slow.