OK until things go wrong.

We enjoyed 2 pretty good holidays with James before we had our duff one. But the Villa that they sent us to had serious issues.
The worse of the issues was a smell of raw sewage. This was recognised by the rep prior to our arrival, but she couldn't do anything about it as it was peak season and they had nowhere to move us to.
The main issue (above) was the only REAL reason for us to complain, we're a pretty liberal family who can make the most of a bad situation, and we would have put up with;
The Ant infestation... we threw food away, but hey ho we were abroad.
The state of the villa ( it wasn't particularly clean ).
The poor levels of equipment (one wine glass in a villa meant for 6) and a melted toaster.
The Camp bed in the master bedroom!
The flickering lights and dodgy electrics.
The yellow stains on the kids bathing suits from the pool?
The sticky windows and numerous missing keys!
But all in all, it was mostly poor because of the stench. We raised the issue with the rep while we were there and the problem shifted part way through the holiday from one bathroom to the other. (The U bend was swapped in the first one), so we shifted our stuff to the shower room, which originally was uninhabitable.
As advised by the rep, we raised a complaint as soon as we got back. After months and months of email communication, we were finally offered 16% of the TOTAL cost as a refund. They ARGUED (a lot) that this was 30% of the cost of the villa.
This offer of compensation suggests to us that they simply aren't interested in customer care.
Our two kids are 9 & 11 and to send us to a place that is 30c+ whilst taking over £2k off us we find leaves a pretty poor smell in our nose!

My Dad used to say to me, You can only really tell how good a company is when things go wrong.
From our experience James Villa's really aren't very good when things go wrong.