noob advice on re-mapping

[Banzai_Joe]

Hi all,
so my pug 3008 GT (2017) 2L Diesel auto 180bhp, obviously out of warranty. I was thinking of having it re-mapped. Only because a guy on our local FB page is advertising it. I did some digging and looked at about 3 websites that all calculated an increase in BHP and Nm of approx 14% for my vechicle, with a fuel saving of only 6-9%.
Most prices seem to be between £250-£300 (depending on their "deals").
So....is it worth it?
Will i really experience a performance boost?
Do decent installers guarantee their work?
Any side effects?

I've just booked in for my MOT and service with my local (and trusted) garage and asked the guy there, he wasn't a fan and said if they "know" its mapped they cannot perform an MOT on it.

Seems to be a lot of conflicting info out there, so thought i'd ask the revheads in here for some honest opinions.
I'm really only doing this because its out of warranty and i can't afford a new car yet so wanted to feel like i'm getting a boost from it so to speak.

Many thanks for all advice offered.

 

[Banzai_Joe]

thank you all so far, very insightful and i'm learning quite a bit from you guys.
I'm leaning towards NOT having it re-mapped now

Oh and to be clear, i wouldn't have used the guy down the road. It just got me thinking about it is all. There's a proper place not too far from me that does the full works, but still......not convinced yet.

 

[Banzai_Joe]

So, got an a reply from the guy in the village doing it and tbf to him he said i'd probably not experience a great deal of benefit and advised not to bother. So........... i think i'm done with this venture.

Thanks for all your input folks