I wish I had come across this thread before I used JL for carpets. It's been really disappointing and I definitely wouldn't recommend JL so I hope my recent experience helps someone who is thinking of using JL for carpets.
I had to do a bit of chasing for the estimate and amendments, and it took some time to get a fitting appointment but I understand that home working/restrictions contributed to that.
On the day of the fitting the fitters wore outdoor shoes without cover shoes to fit new bedroom carpets, left a coffee cup on the carpet which made a ring, chipped the wall, put a piece of furniture back in the wrong place where it doesn't fit and scraped the wall, took a chunk out of the skirting and left glue on another piece. They left an absolute mess and put the furniture back on top of the mess that took us 4 hours clean up and for some reason went in the bathroom (after already going to the toilet in the downstairs one) which meant we had to clean two bathrooms after they'd gone. They didn't seem to follow any of the safety guidance JL sent me beforehand.
On top of all of that the measurements for one of the carpets were wrong and now we have to wait for a different fitter to come back and finish, and they didn't lay paper lining with the underlay that we've paid for.
We made a complaint about the damage (but not about the mistake with the measurements as these things can happen) and the T&Cs around not being liable for minor damage were quoted to me. I have now escalated the complaint, and although I now have a new date to finish the fitting, it has been frustrating to try and resolve the other issues. I know that the fitters are not JL partners but I expected a basic level of respect in my home.
The carpets are nice but the damage and mess means I definitely wouldn't recommend the fitting service.