I’ve had mine for two years daily use, and the only time it struggles with only 4GB is when doing heavy stuff in Windows in Parallels whilst also doing heavy stuff in MacOS. That said, the SSD is so fast, paging isn’t the brick wall in performance that you’d get with a traditional HD.
The only faults I can pick are it can get very hot, which can be a problem if it’s also hot weather (guessing not such an issue in the UK…) The trouble is that its main cooling mechanism is using its aluminium body shell as a heat sink, which doesn’t work if it’s upwards of 40C outside! The battery’s not as good as it used to be after two years also, and as it’s non-replacable, I’d say that’ll be what will limit its usefulness for me in the longer term. That said, I still get 6-8 hours out of it if not using it for CPU heavy stuff.