Cold start and idle are probably 2 of the hardest things to nail with standalone. I played with them both for a few years when we first started doing Suby builds (probably been 12ish years now), and prior to that I played with on on CB's variations of EFI. No matter what I did I was just never happy with it, and just when you thought you had it dialed in, along comes a cold(er) morning and it was all back to square 1. Don't get me wrong, I absolutely understand the benefits of being able to tune completely, squeeze that extra power, accommodate for short intake and custom exhaust, etc, etc... but I still swear by the stock ECU for usability and the aforementioned start/warm-up parameters, when it is available.