In and around a massive house renovation, a corner of loft-space has seen a growing pile of 'Railway Boxes' collecting dust - of which I have an inexhaustible supply....!!! The dust that is... Most of the contents of the boxes, almost without exception, are used. True - some are little used, but not truly new. I'm more than happy with this approach, as one get much more for very much less.
My unusual mixture of 4mm in both OO & P4 means that, for the most part the OO stuff is RTR (75%RTR) - The P4 is either kits to build - or kits to convert, with a little RTR to convert where practicable (25%RTR)
Whilst buying new P4, RTR is not possible. I have bought a few OO items brand-new, and in doing so, it has raised a few interesting issues;-

My first was the Oxford six-wheeled 'TOAD'. Very nice. Next came the Heljan GWR Diesel Railcar - again, very nice - and I see online that folks have already managed to convert some to P4, a useful possibility for the future then. A few weeks ago I took delivery of a new Bachmann GNR Atlantic - this being to use the same set of GNR coaches as the Stirlings. I've also an arcane interest now in Atlantics (Such as the GWR's De Glehn's, of which I am building two.) as well as Singles. Anyway - it's a great model apart from the bent conrods to clear the motionwork, which is arguably unnecessary.
Yesterday my Heljan GWR 4700 arrived - and very splendid it is too. It's taken rather a bashing in the RMWeb forums - mainly, it seems owing to damage in transit. I'm happy to say mine was undamaged and runs very well indeed. It's a great model, and looks much better 'in the flesh'. True - they had forgotten to add the GWR loco-number to the buffer-beams, but it was otherwise perfect. Result...!
Now - on order, I have the Rails' LNER Dyno' Car, as well as a couple of he Rapido Stirling Singles, with sound. The Stirling's haven't been bashed yet, but the LNER Dyno'-Car is currently getting rather a pasting in the forums here for the supposed lack of lining, about which there has been much debate. This is a pity, as this is another superb model. Judging from the photographic evidence - it seems the pre-war Mallard record-run version should have been lined - and now it looks as though even the post-war Loco Trials version was still lined. The jury is still out - but those are the indications. Much has been made of the consultation of 'experts'. Now, I have many decades of building/rebuilding in another area of historic transport. Something that I have learned the hard way is that many experts, like me, are rather self-appointed. The moral is clear, - by all means consult the experts - but ask them to point to the historical evidence - then make an informed judgement yourself. Their 'opinion', on it's own is next to worthless without the back-up of trustworthy contemporaneous evidence. Modern tomes are frequently wrong. I've even found reams of mistakes in respected autobiographies written by people employed by the firms that made XYZ.....

Trust the evidence left by the people that made the history - or the documents or artefacts that remain today. What's needed is real evidence created at the same time as the object in question - not mere opinion. Human memory may fail, but hard evidence will not. If I'm asked, I will often have an opinion, but I will also have a contemporaneous document or artefact to support this, or else it comes with a clear health-warning.

Anyway - my real point here is that, even in my dotage, I have learnt a valuable lesson - which is that all this 'pre-ordering' malarky is great for the retailers, but a risky gamble for us punters. I will not be participating any further. I'll let the gamblers find all the issues before I make a punt and risk my Coin of the Realm.....
As for the Dyno' Car - I still look forward to it, and frankly, I suspect that the lining - if correctly scaled would be almost invisible in any case.
The Stirlings have been preceded by samples, and thus far, they seem to have been very favourably received indeed - but this may not have been the case of course...... I saw some Hornby mag' video, and the sounds seemed very good too. A GNR train of teak six-wheelers, double-headed - with sound... What's not to like...?

(Edit;- Having looked at some further Posts such as Mike Tice's a 492 & Coachman's at 494, it's Game, Set & Match. It clearly was lined until the post war 'Restoration' - no doubt whatsoever. In fact- re-watching the Pathe film etc that was panned in the thread show Mallard sat there - and the lined DC next to it at 7:33 - if you need further proof - just freeze-frame the video there. 1950's & '60's were not a great time for restorations, but in fairness, we easily forget how today, we can summon-up data an the flick of a keyboard.).

https://www.youtube.com/watch?v=QqmYFotXqDg