I've had mine for almost exactly a year now. I'm not a heavy user, but I do use it in preference to my phone for armchair browsing.
When working, it spends most of its time plugged into my Mac to show my CCTV camera views. It's usually unplugged for a couple of hours when I'm on my treadmill (showing said CCTV views), and also in the evening and during my lunch break.
According to the CoconutBattery app, its current charge/full capacity charge are 4,889mAh with a design capacity of 5,124mAh, whatever that means. And it shows a 95.4% figure beneath "design capacity".
The cycle count is 102.
Anecdotally, I don't feel like it needs charging often, but that's probably because it's plugged in most of the day so is always "topped up". The other day I had it doing the same as usual but it wasn't plugged into the Mac (I was doing some iPhone work instead, so the USB port wasn't available for a couple of days) so the battery did go down. Eventually, one evening, it did start giving me battery low warnings, but the battery seemed to crawl from 7%, to 6%, to 5%. I didn't feel any urgent need to plug it in.
Hope this info is useful to you.