I don’t understand the use of a rake of air con Mk3’s for something that’s enthusiast marketed…
If I’m out for a tour with something like a 40 or a 20 I’d like to be able to open a toplight (not necessarily stick my head out and listen to what’s on the front)
Otherwise I may as well stick a pair of ear phones in and just listen to the soundtrack of one at work.
I would also personally take mk1s on something of any personal interest (given mk2 PV stock has mostly had the chop) or even more so if I were in the shoes of the party trying to fill a train of interest to enthusiasts, as it could then be the difference between filling the profit margin, BUT the whole IC thing is born out of trying to find sensible sideline uses for the purchase of that stock (given the electric only offerings are harder to sell so can't run as frequently) add to the fact it's owning company only has one incomplete Mk1 set in traffic bolstered with air cons.
The intention was always to limit the operating days of the "much older" mk1s each year too so was surprised to see anything much non steam using them and it fits with that statement that's its virtually barred from diesel enthusiast uses. Add to the above the non air con stock being harder to police with tightened behaviour rules necessary to enforce these days, even if the behaviour of 99% of passengers doesn't need heavy policing these days.
Eventually all vestibule windows on the mainline will likely remain permanently sealed shut with internal handles (as per some of the Pullman coaches knocking about) so the old nickname "coffin" will be more accurate on air con stock and when the equipment packs up you can forget being ventilated unless hopper windows can be funded.
It's a case of take it or leave it (and as the trains are likely to be of little interest to me looking at the programme style and how the whole thing is set up I can leave it easily without a moan or criticism towards the concept either way).
There are still several other (mostly) Mk1 sets knocking about catering for the acoustic sounds market, currently with a sudden 1990s style class 50 bias as they are the only diesel thing the well financed LSL "trainset" hasn't tried to take over YET. A proportion of stuff elsewhere using mk1s, when not steam, caters for the acoustic heritage diesel following. The Mk3s can still be thrown out by the like of LSL more for the less fussy (on that side) who want every "big" recreated or unusual/rare or "never been done" type working who then simply want the statistical or psychological pleasure of knowing they were on it and a few pics at either end.
You also get an overlap into the markets of folk who want such itineraries in sealed/modern comfort and aren't as keen on mk1s (many of whom can take partners or family members more easily then)... And finally the day tripper market who want first class non dining will also consider many of such trains helping replace those enthusiasts who only use/used Mk3s on service trains to get about years ago or if they needed to be on a one off rare working etc.
All the same, am glad you have had a good day, @Iskra. 
Those prices seem unreal!
