I cannot speak of this company one way or the other (never heard of them, in fact) but as a totally general comment it is almost impossible to find a UK aircraft maintenance company, or an avionics shop for that matter, on which all of their customers (those that you can locate and contact) will report positively.
If you can get 50% "good" reports then you are doing exceptionally well.
It's easy to keep one's plane legal. Just send it to a maintenance company at the appropriate intervals.
But, having been an owner for 8 years now, I've come to realise that the only way to keep one's plane working properly and to assure that the various airframe (mechanical) parts reach their proper design life of many years, is to go for the absolutely cheapest bare-bones Annual, and implement a progressive maintenance regime at the 50hr check intervals.
Unfortunately this assumes the owner is technically savvy and willing to build relationships with trusted freelance individuals.