Tyres. Tyres all the way. That’s the combination I run on my meta 29 and my god it makes it feel sluggish. It would cripple a Solaris.
Where do you live? If it isnt somewhere too rocky spesh control casing tyres are a pretty good balance of weight, life and tread. In the summer I tend to push it a bit- using ardent/thunderbird.
My Solaris has wandered up and down the weight scale the last few years and ive settled on something middling- pretty light wheels, 1x, dropper and the lightest tyres I think I can get away with for the conditions .
You can get pretty weight weenie or burly and ive ridden ones built up like that, but for my money the Solaris is a great ‘middle ground’ bike