I had oem Bosch, and started getting all kinds of misfire and timing corrections, and would throw the car into limp mode. Picked up eldor coils from fcpeuro. Never had an issue. If i didnt get on the group buy for pr id still be running them, but the time was right considering im waiting on my docrace kit. Thats just my take from experience, not hear-say, and joining the bash with no experience. I have read posts however bosch coils cause issues.
I definitely believe you that putting in the Eldor coils had your car running better, no questions there. And I'm 110% not trying to discredit your opinion or say you didn't experience anything because I know how good it feels to have your car running better. But how many miles were on your Bosch compared to the Eldor coils? That, and the fact that many people for years were okay with ordering coils from eBay and/or Amazon where fakes have been known to circulate has me believing that the Bosch coils aren't inferior themselves.
From the years I've spent on various N54 forums and now seeing the FB groups, the typical order of events is usually:
A) Nowadays: Poor running or misfire after many many miles on factory-installed Bosch coils -> swap to Eldor/Delphi because they're the current OE coils -> better running due to brand new coils = "oh wow, these Delphi's really are better than Bosch's!"
B) Nowadays on FB groups and amongst new, high mileage/low budget owners: Poor running or misfire after many many miles on factory-installed Bosch coils -> buy new plugs instead of coils to save money, still experience poor performance due to worn coils-> finally suck it up and buy new coils (usually Delphi or Eldor due to "groupthink") -> "oh wow, these Delphi's really are better than Bosch's!"
C) a few years back/occasionally still on EPost: Poor running or misfire after many many miles on factory-installed Bosch coils -> buy cheapest Bosch coils available online despite sketchy Chinese seller -> issue might be fixed for a while, might still perform poorly -> suck it up, spend more on new coils from FCP (again, usually Eldor or Delphi because of online groupthink + new and shiny) -> "oh wow, these Delphi's really are better than Bosch's!"
I'm just saying I think the echo chamber is indiscriminatory with whether it reverberates good info or voodoo. For a long time people were saying the 2-step colder NGKs were the best plugs, and to always gap your plugs at .022 or less. Same thing with the factory airbox supposedly producing better power than cone filters because of colder air. Now it's common knowledge that's not the case.
I run an E50 blend and have pretty high miles and have only ever had misfires and rough running on old coils, regardless of brand. Shit, for a while people were spending hundreds of dollars on "plasma" coils and swore they had far better performance. From the hard evidence, it turns out the only difference was the plasma coils had red caps and performed better solely because they were newer.