Handling
The Volvo V70 and the BMW 3 Series have approximately similar tires.
With their comparable turning circles, the 3 Series and the Volvo V70 definitely handle about the same into and out of tight spots.
Drivetrain
The BMW 3 Series's engine is markedly larger than the V70's. Note that more massive engines may use more gas than smaller ones.
The 3 Series could learn a lesson or two from the Volvo V70 with respect to pickup.
Torque is the force that lets you accelerate quickly, and in this respect, the Volvo V70 is significantly more powerful than the BMW.
Utility
The Volvo V70 is likely a better choice than the BMW 3 Series regarding hauling capacity, especially if you often need to carry a lot of cargo or large pets.
Drivers with frequent child-duty might favor the Volvo over the BMW 3 Series.
Comfort
While the front cabin in the V70 offers a bit more head room than the BMW 3 Series, there frankly isn't much of a difference.
While the rear of the Volvo V70 offers a bit more head- and leg-room than the BMW 3 Series, there honestly isn't much of a difference.
Dimensions
The BMW 3 Series is a tad heavier than the Volvo V70.
The BMW 3 Series's tank is about the same size as the Volvo V70's, though the Volvo V70's is a little bigger.
The BMW 3 Series and the Volvo compete for the same parking spaces.
Cost
The BMW isn't much more expensive than the Volvo V70 with respect to MSRP.
Overview
The Volvo V70 and the 3 Series have the same basic after-sale protection.