Family was visiting right after I downloaded the Gen4 power update and didn't have a proper chance to test it out until now. I have been following this thread daily however to understand it better.
For aggressive riders there is a major flaw. I have looped out dangerously twice over the past 12 days narrowly avoiding serious injury. Understand, I have never looped out on these two 4-5' steep up sections for over 30 years. I was completely taken by surprise and didn't understand what was going on the first time, but after the exact same scenario the second time yesterday I knew it was not me but the new software.
Before the OTA update I could always count on Turbo 100/100 getting me up these sections easily. After update there is a night and day change. Here's what happened: When approaching steep ups, the technique is to accelerate rapidly, in Turbo 100/100, in gear 3 (third easiest gear), spinning up the lower half. Then, as RPMs slow w/ the grade, you can just make it all the way up in Turbo 100/100 as long as you keep the pedals turning, no matter how slowly. But just as robikinkela has described, after updating you suddenly hit a "power wall" half way up. The pedals just freeze on you. You end up pushing with everything you've got, but instead of continuing up as before, you loop out w/o warning before you can figure out what's going on. It's like "WTF, what just happened? I've never had this before." Maybe Specialized is trying to keep the bike from shooting out from underneath us with the added power? That would be reasonable but it's too excessive a change I think.
Both of these crashes came on a lava flow ride with large lava chunks scattered everywhere around the trail. First crash on a 5' very steep up, I came down on my back hard on a large lava rock smashing my right sacroiliac joint. If I had landed on that rock a few inches more centrally I could have fractured my spine, possibly been paralyzed from waist down. Spent the next 12 days living/sleeping on ice pack, max doses of Ibuprofen/Tylenol.
Finally got up to ride again yesterday. Went around the first crash site but the same thing happened on the next one. I immediately recognized what was going on and w/ flat pedals I pushed back off the saddle as the loop out started, and managed a couple backpedaling steps before the weight of bike pushed me over backwards. Fortunately landed on a rare smooth lava plate and rolled backwards twice but with no injury. Thank God for strong durable skin suits or I would've been bleeding profusely with the lava taking skin off.
I have attached my assist settings to make sure I don't have them wrong. Please let me know if they should be changed. I do not use micro tune but basically the settings I have are close to the preset race settings (No time to waste). Eco is 100/60.