I've had Goodyear Efficientgrips and Eagle F1 Assy 2's on my Mondeo.
The Efficientgrips had decent grip but the sidewalls were too soft which made the car feel disconnected. They also caused steering vibrations which I never got to the end of. They also wore out at an astonishing rate!
I had 4 Eagle F1 Assy 2's fitted and 2 of them went out of shape after just 3000miles. The tyre shop insisted this was something I have done and wouldn't replace them!
They also had very soft sidewalls and made the car feel very 'floaty'. But they did last much longer than the Efficientgrips!
I still have 2 on the rear, one of them is out of shape but has been balenced out so I feel no vibrations.
I would reccomend Dunlop Sport maxx RT's or contisportcontact 3's.
They last well, are quiet and offer good all round performance.
I always pair up tyres on axles. Never just replace one tyre on an axle.
If I have an irrapairable puncture on the front of my car I would replace both front tyres.
Might be worth getting 4 new tyres and rotating them every 3000miles (Which I believe the manual reccomends if you have a look).