I've had an Orbea Gain for over 18months and followed several forums about them since. Personally I'm very happy with my Gain and reading the said forums there are very few genuine complaints about them. As Orbea and
Ribble use the same system I wouldn't expect to hear anything different about Ribble, so it really comes down to the spec of the bike you want, what you're looking for, your relationship with your LBS and of course price. I don't know that deals are about now, but a couple of months ago there were some very good Orbea deals being kicked around the internet as dealers sold off thier 2019 models. Either way, just remember that the X35 Ebikemotion systems both use is power asssit rather than power you up the hills type of motor.
Have a look under the Electric Bikes section for more opinions on the Gain. We're currently up to 50 pages on the main thread!