You can check the order of Shimano road bike components (cheapest to most expensive) here:
Shimano Road Component Hierarchy | ChooseMyBicycle.com. They have a similar list for the MTB components. The Mirage Tour has Claris drive train components which are
2nd from the bottom in order of quality. The Elite Adventure has MTB components so they are not directly comparable but the Shimano Alivo and Deore are mid-level components. Mid level components do work better than the lowest entry level crap. Once you get past mid-level the increase in price is more related to finishes and weight than in having the part work orders of magnitude better. I'd go for the lighter bike WITHOUT suspension. You can always upgrade individual components but you can't shave the weight off a bike without spending $$$$. How often you shift depends upon where you ride. I ride in an urban area with lots of traffic control devices such as stop signs and traffic lights. The very first thing needing replacement on my trikes were the shift cables. I'd never settle for anything below Shimano Deore or the SRAM equivalent.
I owned a Motobecane Mirage and their most expensive factory bike the Motobecane Le Champion back in the days when it was a French made bike, not one where the name is owned by a conglomerate and made in China. The Le Champion was an exceedingly fine bike. I kept mine for two decades and only gave it away when I finally realized I was never going to ride it again after being seduced by recumbent bikes and trikes.