My 1998 V70 has just reached 70,000 miles. It feels like it's time to replace struts, at least in the front. It lost some of the roadholding as well as wind resistance. Has anyone replaced their struts around that mileage? Also, any advice on the replacement struts? OEM, Bilstein, other? Any and all input is appreciated!

Avpman

Norman is right, unless you see any of those problems, don't mess with them.
I just removed one on my 98 V70 at 98K, it was very noisy. Some specialized tools are needed. I also have a 95 850T with 190K and no problems at all.

"roadholding as well as wind resistance"
........usually has nothing to do with struts or shocks. Those struts usually last a very long time, actually most 850, X70 owners NEVER replace them as they don't just "go bad" like the old Goodyear and Firestone adds would like you to believe.
Unless they're noisy, binding, causing the car to bounce excessively, leaking oil.....there's no good reason to replace them.

Tires are more likely the reason why your roadhandling might seem to have decreased.

Many who buy Bilsteins later report that the ride is too rough and that they then feel every crack in the road so I wouldn't rush into those.

Unless those bad boys are leaking---I wouldn't replace them until about 150K miles or 7 years which ever comes first!