Phill they both have their quirks, OOTB the Easybuild look better because of the etched window frames, and there are some stops etc missing from the JLTRT sides, but I found the JLTRT easier to assemble, as you dont have to faff about filling the sides and adding hinges etc. Cost also comes into the equation if you want a dozen and the Easybuild wins there.
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I should add that personally I still prefer the JLTRT once the windows have been sorted. It is a crying shame that Heljan made such a cock up of their mk1's otherwise they would have been ideal for long trains