I also ride down some nice singletrack but changing gear doesn't even come into it (perhaps you should really consider going ss). Ok you click buttons and gears change but you didn't say when did you? I like my gear changing to be crisp and accurate and I found that with SRAM/Shimano that just wasn't the case. If it isn't then I'd just rather have the one gear thankyou very much.
Of course it's all a huge waste of money. What isn't? So Dylan you shop exclusively in Aldi and wear clothes from Lidl do you? And you drive a Nissan Micra 'cos all other cars are just waste of money?
" Riding down some nice bit of single track do I think that was a sweet gear change ?? NO !! "
But if you get to the bottom and go round a bend only to find it goes steeply up again you will be grateful if you have a top end gear system that will make multiple changes under pressure and without fail . Alivio is probably ok for most of the time but it,s just that important 1% of the time the best just works better and much more consistantly.