I've just done the best part of 1000 miles in 2 days on the motorway - very very exhausting, and will not be doing again.
Tank bag was handy as it allowed my chest to rest on it hiding most of me behind the screen. It also helped my bum as I found it much more comfortable lent forward and low (like a foetal position) than sitting up straight like a GS rider. I did have ear plugs, but I always forget to put them in. I get on the motorway and remember, tell myself I need fuel soon anyway, so will survive until next services. Get to services, fill up, have a drink, get on the road...... damn, ear plugs! Rinse and repeat until I get to destination. When i do actually remember to put them in, they help a great deal.
I was finding 100 mile sittings on the Fazer were my limit, any more than that I needed a break for 10 minutes. Would love a comfier seat or seat addon, but my normal commute is 3 miles so don't want to spend a fortune on something I only need once in a blue moon.