Some thoughts on modelling scale aircraft
In a nutshell, I build for space, so 1:72 is my usual scale though there are some kits that I'd do in 1:48, (like the Panavia Tornado), if I'm in obsessed mode. Some modellers can't feel comfortable in the smaller scales and some just have to build the largest scale they can. As a very loose rule, the larger the kit, the more detail you will have in the moulding. In my case, I take that as a challenge and try to add missing detail, (where it can be seen), by building parts from scratch, using a drill to open up gun ports etceteras or by using scraps of material like aluminium foil, fabric, metal wire, matchsticks and so on to enhance the kit.
Obviously, when your masterpiece is complete, you'll likely want to keep it somewhere either on display or in a box somewhere. The simple fact of the matter is that bigger scales of the same aircraft will take up more space! I am a bit of a Tornado nut so have the aircraft in 1:144 (<10 cm long>), 1:72 about 18cm long and now 1:48 at around 35cm long. So plan ahead, consider doing naval aircraft with the wings folded or take the rotors off displayed helicopters. Big units can of course be mounted on a wall using a variety of hooks.
This is a hobby that can lead you to some serious cash expenditure. Again as a a general rule, bigger kits cost more, (cost of plastic, bigger capital investment in moulds etc. This isn't always the case, an F-4 Phantom in 1:48 from the early 90's will set you back less than the latest 1:72 offering. This may seem like good news but you may feel need to update the older kit with after market parts which will definitely end up costing you more.
I don't know why, exactly, but the time I spend on a kit, (whatever the scale), seems to be consistent. Bigger kits need not take any more time to build then smaller ones.