Mate bought the ex BMG XC70 3.2 with over 3900K on the clock and its brilliant , gets way better economy than my T6 3.0 and he has very little trouble drives a mix of long country drives for working week or in city for local jobs. He loves it. He had a few P80 wagons before this.
Missus has an S80D5 and drives it like she stole it so less issue with EGR. Knowing you can do the work,you can easily clean out the EGR yourself , always run a cleaner though it in fuel or in the manifold , always use a good fuel supplier and i would get a tuning box for it , one that plugs inline if i drove it a lot as coming from the T6 with instant GO off the line the turbo lag is elfin annoying! BUT , you get used to it.
If i were you id chase the few XC7070T6 that are out there! One came up at Berrys recently. Check @iceton1975 , Mark about it?
Going by my mates XC703.2 fuel figures , its about similar or not far off the D5 somehow! In that case , id leave the D5 alone as swirl flaps and EGR make D5 less desirable in long run?