I hated bottling with a passion due to 10gal batches and went all keg. Kegging was awful for parties/transporting beer for me because you think you'll be happy taking a warm keg somewhere and it turns out you've become a beer snob and irrespective of disturbing any sediment on the bottom of the keg in transport you now require your exact temperature and carbonation for a perfect pour or else you regret serving it. It just didn't work out like I thought for me, but the quality control on my beer is much higher.
People also don't care that much and will drink whatever is around at parties rather than wait for a slow/foamy/fussy pour. At least the ones I go to! I could make a weak golden ale or something, serve it warm and mostly as foam, would rather not tbh.
I've had quite a bit of success bottling from keg when the beer isn't quite carbonated enough. I have a hell of a time doing this with heavily carbonated beer, but there is a sweet spot with slightly flat kegs which allows me to fill plastic pop bottles at a steady rate if everything is almost freezing cold. This is the easiest way to take beer to a party.
I wouldn't go back to bottling, but can see the positives in both methods greatest when I'm separated from the negatives. I've got some bottled beers which are almost 2 years old now and I'll never have this with a keg. I can't see why I would keg a brett IPA, but still .. if you brew imperial stouts and stuff, hard to justify tying up a keg. I've brewed high adv imperial IPA's which I was initially very happy with, a third of the way through the keg? Really tired of it. Easiest kegs to kick in this house are session beers, ones on the weak side, fruit beers, sweet stouts, porters etc.
I went reconditioned because I didn't know enough at the start to diagnose and fix potential issues so I wanted something with the greatest chance to work without paying full price. I wasn't brave enough to buy a bunch of used ones. People will tell you otherwise, but even 'working' kegs can leak. I've got 6 and they have a mixture of threads on the posts, mixture of poppets in those posts and a mixture of gaskets. I'm slowly standardising them, but I've got ones that won't take universal poppets and the posts are threaded 'funny' and new posts are quite expensive. There is a slight learning curve and as a result I'd recommend against buying just one of everything. I've needed a literal keg spares/tools kit, you'll want spare gaskets, poppets, posts etc if you get into them. I've got a tub of random pipe, push fit fittings and other stuff to suit. You'll always realise you needed another stop tap or check valve or something. I filled one keg and realised I couldn't get the beer out poppet to seat so had to leave it with a beer connect on with a stop tap. I'd have been stuffed without the spare tap and connect.
I started thinking one keg, kept outside in the garage or in my fermentation chamber between brews with a party tap and a 4.7kg co2 bottle with duel regulator was going to be enough. Now I run 4 in a dedicated kreezer with compensator taps. I've got a gas distribution manifold, stop taps for all beer lines, check valves on the gas sides and so on. I cannot say at this point it is less hassle than bottling overall. It is certainly less hassle to package though!
Parts ..
Gas bottle. Get one which fits your setup and one which you can easily and economically refill. There is no point investing in something you cannot get refilled locally and that (at least here) decides almost everything else. It can be harder than you think to get hold of them.
Regulator. Duel stage. I paid about $30 for one and it is acceptable. I've got much better $50 separate primary and secondary ones at work and they are much more accurate, but they were 5 times the price. On mine I can not really set lower than 6psi and my accuracy is within 2psi. At work I can set whatever I want.
I initially used 3/8" for everything because I've access to the fittings and pipe. It is also really common for the gas and beer posts here. I've switched to a lot more 5/16" stuff on the beer side in the quest for the perfect pour and I've now decided to switch to 3/16". There is an art and science to designing balanced beer lines. It is best to see what you can get economically and then use that, it might be better to use tons of 3/8" if all your fittings are 3/8" instead of buying all 3/16" in order to save on some 30c a metre tube.
Decide how the layout is going. I go gas regulator to 3/8", 3/8" one way check valve, 3/8" T, gas posts and further 3/8" T with plugs when kegs are not in use. I used to have taps on all the kegs for the gas side, but don't care if they can talk to one another now, just don't fill past the gas tube or cut it short, or blow the beer out of the gas lines into the original keg when you pressurise the system instead of other kegs.
Beer side is beer post to 3/8" tap, 3/8" to 5/16" reducers, 15' coil of 5/16" cable tied up, 5/16" to 3/8" reducer to compensator tap. The tap allows me to shut off the beer for safety, I don't like disconnecting beer posts as they tend to spray a little beer into the kreezer.
