I have the Pinnacle and the DaVinci - don't have the Ascent. I really like the Pinnacle a lot and think that it doesn't get the respect that some of the other portables get, but that doesn't mean it isn't a great vaporizer. For me mutiple temps don't matter, having a high and low setting is enough. The Pinnacle is simple, easy to clean, very portable and works well. You don't get thick clouds of tape if that's what you are looking for, but it gets the job done.
The DaVinci is enormous and heavy in comparison. It's harder to load and clean. It gets really hot so you can't just shove it in your pocket or put it down anywhere. You do get slightly thicker vape. It's great in a lot of ways, but its not as portable or as simple as the Pinnacle.
Of those two, overall I prefer the Pinnacle as a portable. I'm probably not going to get the Ascent any time soon if at all. It looks way interesting, but it has been described a cell phone sized, which is still large, and the price is high - it will go down.