I've been using Braun shavers since I first grew enough facial hair to justify one (actually probably slightly before that moment) and I've always found them well-designed and very reliable, I've never had to replace one because it broke or wore out, only because I wanted the newest features. The PocketGo M90 keeps up the Braun design standard with some clever design touches - the foil-guard keeps the foil protected but also locks the shaver switch, the supplied cleaning brush is stowed in the base of the shaver so you never lose it and the sideburn trimmer, although small and a bit tricky to use, is a nice inclusion in such a small and affordable shaver.
The shave you get is surprisingly good too, rivalling an entry-level shaver, although it does miss some stray hairs and you might need to go over areas a couple of times to catch them all. It's ideal as a secondary shaver for your desk drawer or briefcase but it's also good enough to take on short holidays as your only shaver. At this price it's also much less painful if you leave it on the shelf in the hotel bathroom...
The foil on top does seem a bit fragile - it's very thin, which gives you the close shave, but doesn't look like it would last as long as the foils on Braun's main range and that could be a problem. I can't find anywhere offering replacement foils or cutter-blocks for this shaver and some users claim Braun have stopped offering them altogether. I'm sure there are some good economic reasons why Braun might have withdrawn them but there are better ecological ones why they shouldn't. It's a great little shaver for as long as the foil lasts but if the foil wears out or gets damaged does the whole shaver become instantly disposable?