I had a carp experience of them, my 2.25 pet started screwing around just as i was lookign for a 200tdi for conversion. needed the beast back on the road. phoned them up to find out how much to get the block/ crank honed.
i was told they dont do little jobs like that but could sell me a new engine for about 1.5k, followed by you dotn want to buy a second hand tdi they are all carp/ nackered you will waste your money, i can sell you one for £....
so instead i went to a local place in surbiton that gave loads of advise with no pressure or carp, examining individual parts to and telling you what to look for.
i had a rebore, new pistons/rings, shells, honed crank for a couple of hundred quid
i now have a 2nd hand 200tdi in the garage thats pure fantastical love condition ( its been rebuilt) so im happy