I had an utterly miserable time the other day with the taps in the downstairs WC.
I knew they were an utter pig to do from the last time I had to replace them due to the mini basin, the work of art piping (proper "this plumber has been doing this for decades job) with hand bent pipes etc, and all of about a quarter of an inch of play, so I'd bought a new tap wrench and thought I'd allow a couple of hours...
4 hours later, 3 trips to screwfix for additional tools, having to hacksaw with about 3cm movement one of the pipes (there was no space at all for any of my pipe cutters, including the "wrap around" ones), and finding out the stop valves in the airing cupboard had seized and they were replaced.
On the plus side I know have ALL the tab wrenches box spanners you could ever need and the downstairs taps are now on flexi hoses with stop valves...
So today I tackled the valves in the airing cupboard, expecting the worst I'd bought several different valves (of a good brand*), I was very pleasantly surprised when apart from having to work the adjustable spanners** about an eighth of a turn at a time I was able to get them in without any issues, and I've left them so the handles are accessible without emptying the entire airing cupboard as the old ones facing away from the door.
I've also set a reminder on the phone so that every 3 months i'll nag me to operate the valves.
It was interesting to note the new Pegler valves (apparently Yorkshire made, and twice the price***) appear to use much heavier metal on the likes of the the wheel of the "gate" valve, and it's a larger wheel with rounded spokes so you can actually get a grip on it. So for anyone else facing the horrors of plumbing I'd recommend looking at them if you need a gate valve, they feel much more sturdy and easier to use than the cheap ones that had been fitted.
*In the end I used the long lever ball valves, and have kept the stopcock and gate style ones as spares.
**Next up for the plumbing box is a pair of spanners that fit the compression valve nuts, I've got a bunch of other spanners in there of various types, but not a "standard" spanner that natively fits them (or better yet one with thinner tines), and I'm not sure how..
***Looking at them they're aimed at commercial/industrial use so presumably heavier duty/tighter tolerances (the ball valves with lever's that I used are apparently rated for air, gas, oil and water).