I thought I'd write a kind of blog to recount my efforts with the Masokits system, having been spurred on to give it a go from the replies here and on the Templot Club forum. I thought it might be helpful for anyone else in my situation. I have made about 7 unchaired turnouts in P4, soldering directly to copperclad or ply and rivet sleepers, and am well used to the practical problems involved with making them actually work, but have till now avoided, and felt zero interest in, the chairing. Seeing Paul Boyd and Bob How's trackwork has changed my attitude there. However I'm very glad to have had the experience making rather basic turnouts before embarking on realistic ones as the intricacies of realism could well have been so engrossing that I would have been unaware of the real model practicalities necessary for good running, as every adjustment after construction will involve a chair too.
The etches arrived about three weeks after ordering. Only cheques are accepted and they have to clear before the order is sent out. Very good instructions are included.
My layout plan includes one turnout where the switch and closure area is off scene so I started with this to get some practice. Some sleepers are missing as they aren't all necessary. It is unprototypical, only the mainline radius is prototypical, the turnout road being shortened to give my minimum radius, with "model" switches in the Templot switch setting.
I started at the switch end, to get some practice at the running chairs, even though the switch area is going to be have to be done carefully or the A length switches in the 48" radius may cause derailments. The switch is gauge widened from the very start or toe by 0.2mm, and there are joggles, which I expect not to incorporate elsewhere.
Running chairs (as used on plain track) are the starting point of understanding the Masokits system. There are two parts or halves to each chair, one outside the rail and one inside. The outside half is the business half, and creates the necessary rail height above the sleeper, and it is suggested to make the whole track, and if necessary fettle it till successful running is achieved, before adding the inside half of each chair.
Point chairs are mostly cosmetic variations of this basic concept, slide chairs being the first exception I encountered.
The etches are totally user friendly and very easy to fold up. Well, compared with a lot of stuff I've made. They require no fettling, nor do the tabs need to be removed - the system is designed to work and look right without the bother of doing that. It's slightly tricky to get the first rail upright and onto the first half chair, but as I was using some rail that was in unwanted EM gauge plastic sleepers it was easy to use a couple of those, raised to the right height with some layers of tape, to hold the rails upright.
The two running chairs were done and then it was slide chairs through the tricky part of the switch, the set to the stockgauge, and these chairs made it all easier if anything. Here I'm using a bit of rail to set the stockgauge.
I make the switch area stockrails the length of the prototype to make them easier to adjust over this critical area. Somewhere along here towards the rail joint (where the the slide chairs are clearly not long enough) the next type of chair is used, which according to the instructions are the extended chairs.

Understanding which type of chair should be used and where, is what has caused most head scratching as I don't have much prototype knowledge and the instructions are brief, rightly saying there is plenty of information out there...but I haven't got it! - till I downloaded a C&L template from the Society and for the first time looked closely at all the chair drawings and locations. So on the C&L template the next chairs after slidechairs are called switch chairs, and after that are bridge chairs. Respectively Masokits call these extended chairs and narrow chairs. No matter, they look right, though I didn't notice the extended chairs had both inside 1 bolt and outside 2 bolt variations.
I started to fixed the rest of the mainline stockrail using the narrow or bridge chairs.
My previous experience has shown me that model rail switches are much less flexible than the real thing and need to be free to move where on the prototype they are fixed down in the point chairs, or else they are very stiff and tend towards a dog leg shape when not closed against the stockrail. For this reason I normally make them long enough to reach the knuckle rail joint and leave them unfixed for the first few chair positions.
I fixed the switch rail to two narrow chairs (bridge chairs in C&L speak) beyond the joint mark. Then I fixed the inside extension chairs (point chairs) onto the rail but not the sleepers. There are "fillers" to represent the fact that the chair is joined to its other half outside the stockrail, but this I will fix to the stockrail and leave a gap for movement.
So that's the progress so far. Of course getting exactly the right chair in exactly the right place isn't going to be the ultimate nirvana in modelling. But it won't look much good unless it's roughly correct