Re: Lumia 550
Same here, I bought one 2nd hand from eBay from a guy who claims he couldn't access the internet on it (It was only a week old or so).
I did an update check straight away which included firmware and wp10 (1.86GB worth!) - luckily this was 2 days before the ill-fated initial release of 14627 which borked some 550's
Touch wood, I've had zero issues and I'm really liking it. My biggest gripe is the weak battery life as even with everything turned off, background apps reduced to email and messaging and glance off it'll lose 10% charge on standby a day without any actual use.
The article mentions battery-life tweaks - here's hoping.