This yard, owned by Richard Matthews, fits out Oyster yachts (and Gunfleet). We went there to have serious leaks around the wrap-around window fixed and the initial upgrades to make Skyfall 'RTW compatible'. The yard is renowned as not cheap but we felt it would be worth it to have results we could rely on. How naive we were!
Good points: 
1. They know how to make a boat look good. Eight years of gelcoat damage magically disappeared and the teak looked magnificent when the boat was handed back
2. They have the original plans and documentation for Gunfleet yachts ( who went bankrupt). They know all suppliers and where to get stuff done.
3. The major water leak from the wrap-around window was fixed and has remained fixed.
4. I believe their rigging expert, Michael Laker, is very competent
5. They did accept mistakes and rectified the issues (which we found last year) without too much argument
Issues
1. In 16 months (we did not sail in 2020 because of Covid) Skyfall had 3 project managers. I understand the first two were asked to leave. Our third Project manager was very competent and finally got things done. But, as a lot of the work was on labour and materials basis, I know we paid more than we should have. 
2. The bimini design was flawed. Originally it was held up by lines which got in the way of the mainsheet. When this was pointed out, the design was modified and that issue solved. But the clearance of the boom was also too marginal. In 2022, to solve this, we have taken out a triangle from the foot of the mainsail to lift the clew 8 cms and add new reefing points 8 cms above the originals
3. As part of a thorough rigging check the mast came off and the rod rigging below deck was taken out for die testing. However, when it was put back, the seal was so bad that water poured in. It was so bad we had to abandon a 'shakedown sail' after just one day, ruining the crew's planned holiday. Second time around the work was done properly
4. Foxs recommended that, in order to make the boat watertight, we should replace the Lewmar windows ( after 8 years). I cannot say if this was totally necessary but, after the work, the boat was initially dry. Unfortunately not after an Atlantic circuit! The Xufre yard (see below) had a look and believe the rubber seals are good, the sealing between the outer metal and hull was good, but the inner metal part was put in with insufficient sealant/glue. So this year they have been taken out, cleaned up and re-seated. So far, so good. 
5. As part of the initial poor project management, the wrong length spinnaker pole was ordered. The solution was to cut out a central portion and use a Seldon kit (with inner sleeve) to join the two halves. The strength of this was questionable and, on the first Atlantic crossing, in Mindelo, we were forced to remake this join. After a few months light work the inner sleeve could be pulled away from one half and there was hardly any epoxy holding the parts together. We put it back and reinforced the joint with multiple sheets of fibreglass mat and west epoxy on the outside. It may not now look pretty, but it seems really strong. Foxs were surprised and stated they used a standard Seldon kit as prescribed and referred the issue to Seldon. There was never a response but they did reimburse our materials cost.
6. Generally everything was very expensive. One example. To put an anchor on the boat, adding colour coding every 10 metres to a 100m chain generated a labour bill for over 1500 pounds!
Conclusions
1. Not for the well-heeled sailor
2. Do not assume that expensive means trouble-free. They have good people; But if someone less experienced is not properly supervised.......