A mechanism that basically didn't work, and Sam gave it 4 stars.
That displays Sam's absolutely relentless bias in favour of Hornby and against Bachmann at its most ridiculously obvious. If that was a Bachmann it would have been a 1, or a two, and laced with endless bitter, puerile jibes about "Bachmann tax".
Whilst I like the idea of Sam's channel, and the service he could do for promoting the hobby, the subtle but extremely relentless bias, is quite ridiculous.
The model he reviewed was criminally poor and should have been portrayed as such in every way, and in no way what ever did it deserve to score better than any model that performed properly. Particularly performed well, on a carpet.