You'll excuse me whilst I pontificate.
Over the years, I have spent quite a bit of money on various bits of luggage - some of which have been good and faithful friends, some of which have fallen victim to baggage handlers and some of which fell apart at the first possible excuse.
Whilst I have a couple of other things tucked away in the armoury, my use of luggage these days comes down to four pieces - which serve just about every need I can think of.
The smallest piece is my laptop bag - now I'm hard on these, cramming bits and pieces into every possible pocket and I've gotten through two in eight years. The most recent acquisition is a Targus Global Executive Plus in a sale a few months ago, it's suitably anonymous (I always felt a bit wary tromping some of the streets with a Sony branded laptop bag), it holds a laptop, accessories, a book, some paperwork and two cartons of cigarettes with ease and could probably be used for a stripped down overnight if required.
The next smallest is the "cabin bag", it's used for trips of one or two nights and has been stretched to three nights before now. It's approved by Lufthansa as cabin luggage on anything but Barbie's Fun Jet or a Crash-8 and was acquired during a bored moment at the Lufthansa World Ship at Berlin Tegel. It's the old design of the Titan Lufthansa Flight Cabin Trolley and comes with LH branding (which has allowed me to whisk through the Crew lane at Sydney). It's advantage is the laptop compartment, although that can be a pain for extracting the laptop at security when full and that it is soft sided and can be crammed quite full - although this can lead to fun with overhead bins on the Fokker 100 with Swiss's best jobsworths ready to pounce and gate check it. The other disadvantage is whilst it will hold a pair of shoes in the shoe holders, the addition of a pair of shoes constricts the capacity to two days. It also gets used as the cabin/laptop bag on longer trips. At two years old and in fairly frequent use, it is wearing very well. I used to be very happy with it, but now I have a terrible urge to replace it which I really shouldn't do as it's good for a few years yet.
The newest item in the collection is what I have now called "Shiny Case". A Rimowa Classic Flight 63L Trolley, it is exceptionally light (4.6kg), very well made and rather stylish. I can see me wailing about every minor dent and scuff on in for years to come. RImowa is sufficiently unusual to get appreciative comments from Brum Taxi Drivers, but common as muck in Germany. Shiny Case is for trips up to a week, or maybe five days if I have to get dressy. A four day Ruhrgebiet with three sorts of clothes, books, various ancillary tat, a pair of boots and a pair of shoes is no problem and there's even some room left for a couple of boxes of choccies for the office. The sticker shock on purchasing one of these beasties is quite large and even more if you wish to pay in pounds Sterling. I recommend searching carefully through on-line German baggage retailers.
The oldest and largest item is my 20 year old Delsey Club. Purchased for what seemed like a small fortune back in the mists of time, the shopkeeper told me that it was a suitcase for life. It only really gets an airing once a year these days, but despite being a bit battered by baggage handlers, it's still in fairly good nick and holds enough clothes for a couple of weeks and still has some room left for gifts/books/etc. Main problems with it are that it doesn't have TSA locks, so can't really be taken to the USA and that parts are no longer available, so if the wheels go, it may have to face retirement. As an old hardshell, it's a heavy beast, so you do have to watch out for the 20kg piece limit found on many airlines if you overfill it.
I'm not off anywhere for a couple of weeks, so I might add some thoughts on aircraft next week.