Alright so my next major service is the Vanos/VCG/Plugs for my ZHP. i have only to order the Dr Vanos unit to complete all tools/parts associated. however, i'm wondering at ~60k miles if ignition coil replacement is also necessary. i realize that the work involved is redundant so the labor to replace is not my concern, only the cost for the parts.

so what mileage should/have you guys replace(d) your coils?

also, i've been looking at OEM v Bav Auto "High Performance" Ignition Coils which they claim increase performance/hp. anyone used these and seen any difference? i'm highly skeptical what if any performance gains can come from coils.