I would have thought it would have been improved performance on descents rather than climbing (depending on the weight). I know our old TR450 ride better than any other bike I’ve ever ridden (DH bike) even compared to newer, lighter bikes as that had all the weight low down and central.
I can’t imagine a much heavier bike climbing better. Might be more stable and planted, but on a long slog you’re still going to be expending more energy compared to the same frame without the extra weight.
I personally think that a bike around 30lbs is light for what I need, but I wouldn’t want anything over 35lbs for general trail riding/enduro/all mountain (current bike is 35lbs and it rides as I want it). But going for a new bike I’d want to stay around about 32lbs without compromising the strength of the components and frame.
Tom KP.