A generalized comment based with experience on quite a few other cars is that in most cases people expect too much and think changing bushings on either one or both sides of the shift cable will suddenly give them a great shifting transmission. If the stock bushings are shot it can help quite a bit, but so would new OEM cable/bushings. Poorly shifting transaxles are usually due to a combination of the shift selector mechanism, internal components like the shift fork design, the shifter assembly, or the cable layout themselves.
I don't know if this would be the case on the IB5, MTX75, or the Getrag 285 transaxles used in the Focus so it may be worth trying. There are some potential downsides as the stock bushings are usually designed to absorb some shock and harsh shift forces that would normally be transmitted to the shift selector. There's also the risk of breaking cables or other shift components by removing some of the play (and just because there's some give in a bushing doesn't mean you can't have crisp shift engagements). If you try solid bushings and it still shifts about the same I'd recommend going back to the stock pieces, but if it does shift better it may be worth the risk.