F80 Paul (Paul Johnson) Stage 1 E60 ECU Tune
As I previously stated, the whole reason I got this vehicle was for the tuning potential. The S58 is a monster when you add a little more boost, timing and ethanol. I did a lot of research on tuners for this platform and even a few other M platforms and F80 Paul continued to pop up.
Tuning Process:
All tuning is handled through BM3. If you already have the license, you will need to purchase the tune at pauljohnsontunes.com and then within the BM3 app, request a custom tune from them.
Before flashing the first time, I ensured to gap down my stock spark plugs to .022 as recommended by Paul. There are a lot of docs out there and it's very easy to do. This is essentially the only requirement to run this file.
I started tuning with him on 4/24/2022 and just wrapped up my final revision on 5/10/2022. Now, that may seem like a long time but my work life makes it challenging to log during the day, the crappy IL weather delays things as well and so does everyday life. We ran through maybe a dozen revisions and adjustments along the way. That may seem like a lot to some but my DA can change drastically so I made the personal decision to send more logs on hot and cold days to ensure we can fine tune as much as we possibly can. After the standard 3-4th gear pulls I wanted him to review my 1/4 mile and launching logs as well to make sure everything was in check. I go to the drag strip regularly so this was a big priority.
My situation might not be the same as everyone else. Most of the time you will likely go through 5-7 revisions and be good to go but I wanted to take the extra step to really dial it in for my uses case.
Communications:
Paul and Nicholas were awesome to work with. They reviewed logs before noon CST every day and I had revisions within 12 hours. The communication was on point, the tune felt incredible every step of the way and I didn't encounter any issues what so ever. From past experiences with different tuners on different platforms, a lot of them like to keep the info and details to themselves. They don't tell you want is being changed or what needs improving and just send you a new file and say "try this". That is not the case here. Nicholas and Paul gave great detail on how each log looked, what areas they were improving and even gave feedback on 1/4 mile and 60-130mph Dragy data in comparison to what they see from other customers. If you are a guy like me that wants to know the finer details, they will surely provide and answer any questions you have.
Driving Impressions:
The daily drivability of this tune feels awesome. After a little seat time and adaptation learning it's very smooth and seamless. Most wouldn't be able to tell a difference from an OEM car until you push your foot to the floor. A lot of people mistaken high HP vehicles to be undrivable at slow speeds or in traffic etc which can be the case for some but certainly does not apply here. I have 0 complaints on the drivability.
Since ethanol burns at a much faster rate than gasoline and the fuel system is ramped up to move even more of it, yes your MPG will take a hit. On BM3 OTS 93 I was averaging 14-15mpg around the city. I live in a city with a lot of stop and go and very little highway 50mph cruise zones. On E60, with the same driving style I average roughly 10-11mpg. It's not a huge hit but lets be honest, you don't get an X3M if you want high miles per gallon, you get it for the smiles per gallon lol.
All said and done, I highly highly recommend
F80Paul for S58 tuning. I wouldn't have had it any other way.
Now... for the good stuff 
I recorded over a dozen 60-130 times to use and compare each file. Granted, DA changes and some comparisons aren't truly accurate but with a little knowledge you can still get a general understanding for how the car is performing at a given DA. I log and Dragy on the same exact road, at the same exact starting point every single time to try and keep the control as consistent as possible.
The first slip is on the base E60 file, each slip following it was a revision. For the sake of this thread I wont upload them all but you can clearly see the progression in power. Keep in mind the DA does change so just because a time might get slightly slower, it's likely due to the increasing DA. The very last slip was from this past weekend at Great Lakes Dragaway. LOOK AT THAT DA!
I knew these cars would get fast but I never expected to be running mid to low 7s 60-130s in the middle of summer with no additional cooling... I am beyond satisfied with the performance of this car.
Here are a few more metrics from my fastest recorded Dragy runs. I'm still getting used to launching this car so I have no doubts I'll be able to improve upon them. It's very obvious in the 60' that this car will go low 10s if I can get the launch dialed into the 1.6s
That wraps it up for this post. I will continue to update my build thread as the car goes faster. Hopefully I was able to address any curious owners out there that have been on the fence about tuning or anything along the way.
Cheers!