APT,
Just a quick follow-up re Sen3 Boost. Brilliant, absolutely brilliant. Light as a feather yet very good comfort wise. Best feature is the forefoot boost. It really feels like its working with the rest of the sole to keep drawing/propelling you forward at pace; the shoes will you on when the going gets tough. Grip is fantastic and, as intimated above, cushioning more than adequate. No pain or discomfort after 2 x 14-15 mile runs. Just joy.
Now I've had the chance to compare Ren and Sen Boost I have to say the former really are more soft and, to me, don't really offer anything exceptional v a number of other Adi shoes.They certainly lack the cutting edge Sen provides.
I know this is no great technical breakdown or analysis but, as you can gather, I'm really impressed with S3B. They are the 'dog's dangler'. And then some;)
Buy them. Wear them. Have success with them. Love them. Like Alistair Brownlee did in London yesterday.