The only issue I’ve come across is with the Android version. When I’m typing in the address bar, Firefox Suggest shows the page I’ve previously visited, but as I continue typing it disappears, then I keep typing, it comes back again, etc. So if I stop typing on the wrong letter to click the link, it’s no longer there.
The worst part is when you wobble slightly and insert the strand of DNA in the wrong place, so instead of curing the patient’s genetic disease they immediately sprout horns.