Don’t have one but have test rode the Gen 3 for a week. I have the second gen SL5 as my winter bike. I was tempted to get one as my summer bike.
Pro’s – wide tyres. Super comfortable for all day rides.
Cons – bloomin heavy. I test rode the SLR with Ultegra Di2 and upgraded 38mm Aeolus wheels (Bontagers top level can’t remember the full name) – with pedals and 32mm tyres it was over 9kgs.
I bought the Emonda SLR instead, similar level build and got it under 7kgs.
If weight isn’t an issue then it really is a very comfortable bike. But that’s the wide tyres, I’ve never adjusted the isospeed setting on mine and I’ve had it years.