Good video. I have a No4Mk1, M91/30 and it's shorter cousin the M44. Also have a 1903A3, M1917 and a Yugoslav M48. I agree with him on 90% of what he says, the Lee/Enfield action is weaker than the Mauser action, but it is strong enough for the job and that is what matters.
I've read that of the bolt action battle rifles the SMLE, with the No4Mk1 being the best of the type, are, or were, the finest of the mix. Although the 303 was less powerful than the 8mm or 30/06 they were more than adequate for the job, the 7.62x54R is it's equal. The No4Mk1's sights are superior to all save the '03A3 and are the equal to the '17's. When it comes to accuracy I'm not good enough to tell the difference. I feel the 10 round magazine is a big plus for the SMLE not only for capacity but because if you end up having feeding problems you can switch out magazines and not have to send the gun to an armorer.