My sister loves her capsule machine, but the coffee just tastes stale to me.
BTW, espresso isn't all that strong in caffeine. The intensity of the favour can make it feel otherwise, but the speed at which the water is forced through the coffee grounds means that it is nowhere near as much of a caffeine hit as other methods, where the coffee and water are in contact for longer.
I have a Vogvigo roaster, a Delonghi burr grinder and an Aeropress coffee maker, and the results are absolutely spot on for my tastes. Rave Coffee (bought through Amazon) supply green coffee beans of good quality, without stinging you on price or delivery costs.