My favourite part of Insurgency 1 was how smooth it felt. That game was butter smooth. Perfect for twitch shooters. You could know exactly how and when every button press, every mouse movement would react on your screen.
Insurgency Sandstorm is the opposite. It has wildly fluctuating framerates. On the training level, I struggled to reach over 90fps. On medium-high settings. On 1080p. With an i7-7700k, GTX 1070 (neither of which were anywhere near 100% load), 16GB DDR4, and an SSD. What the hell? The worst part is that whatever graphical improvements were made to the last Insurgency, they don't seem worth the massive cost in performance. High res ground textures look awful when the occasional 2D low res shrub/grass texture is thrown on them. Everything has texture pop-in. Where did all the performance hit go to? I'm not seeing anything that stands out and makes me go "wow this looks so much better than Insurgency 1", they must be very subtle.
Now I could cap the framerate with Rivatuner like I do for most games, which I did, except usually with most games that makes them smooth. With Sandstorm, it's still not smooth. I'm still getting random frametime jitters all over the place. This game doesn't feel like an extension of my body like Insurgency 1 did, I feel like I'm spending more time fighting with the PC than I actually am playing the game. There are plenty of games out there that had similar performance to Insurgency, like DOOM, or AC Odyssey. But A ) they looked waaaaaay better, and B ) they were SMOOTH. Rock solid frametimes.
The sad part is knowing that this late in the beta, I don't think this is fixable. I think it comes down to the choice to use UE4 as the engine. I'm someone with over 2000 hours in Insurgency 1, I've never looked more forward to a game than Sandstorm, but I don't know if I'm gonna buy this. The underlying game is incredibly fun, but the engine and performance is the bottleneck in enjoyment here.