Running Swiss, Big Balls, Race Reds and NMB's on my setups.
Swiss are Swiss and always what I've defaulted to but I just wanted to give something less expensive a try because corrosion happens fast where I live now (sub-tropical island) and Bones Swiss cost around $85 a set here. The outer races of my Bones bearings start rusting quick here without ever rolling through water so I thought if I could save a few bucks it would be worth it. I've tried the whole wiping a tiny bit of speed cream on them but that just attracts dirt and they still start to corrode just as fast. I'm fine with performing basic maintenance on bearings but as far as spending time doing regular corrosion control on tiny bearing races, not so much.
The Big Balls are disappointing. Noisy, not a good noisy, a cheap noisy and even with spacers they're noticeably slower. Race Reds are fast, really fast and have a great sound to them. I like them a lot but they only work well if the cores in all four wheels are manufactured to spec. One goofed up wheel core and the whole thing goes to hell. Another thing I love about the Race Reds is the Bones Bearing tool actually works as an extractor with them, the little balls lock into the inner race so you can pull them straight out (something you can't do without wiggling if you have individual bearings and spacers). The no washers or spacer chatter is a nice bonus too. At around $48 I'll probably use these on all my precision cored wheels in the future.
The big surprise here is the $22 ($14.99 in the US) NMB's. I decided to get a set a few months ago (haven't had NMB's since the early 90's) when ordering some new Acid Chemical Co wheels from SOP. They're really fast and really quiet. I've been skating them a lot the past few months and they're holding up well. They're completely sealed on both sides so the "no maintenance" claim seems to be holding true. There's also no visible signs of corrosion yet either like I get within a month or two with Bones. I'll definitely be going with these for my budget bearings over regular Bones Reds. Yes, once one goes bad all you can really do is dispose of it (unless you're a bearing maintenance wizard) but where I live I can have the metals recycling pick them up just like they do my old cracked or used up trucks. So I don't feel so bad about buying disposable bearings.
Bearings are always a hard topic. Everyone installs them differently, maintains them differently, spacers versus no spacers etc etc. There's so many variables that can change the experience from one person to the next. This is just my experience as an "always spacers/no wheel play" skater.