I just don't get why Honda did this to people. An adventure bike needs to be serviceable. An air filter needs to be a 10 minute job.
As for valves I'm now 65 and run my bikes easy these days. Just touring/camping and easy cruising. No more hi-RPM stuff like when I was in my 20s.
I can easily run a bike to 80km (50,000 miles) and not worry about valve shim clearance. Last time I checked a set of valves at 30,000 miles the were still fine. So I no longer even think about them.
I was giving the AT a serious look but from all I have seen/read/heard, I may take it off the list. I think I will wait till I can see the Yamaha T700. I like the size, fit, more power then I need but I have got to have a bike that is easy to service.