That is hard to say - if there are many Cybrans in-game then you can expect a very noticeable improvement because of the drones being 3x - 4x as cheap (50 hives are now ~2ms instead of 8ms / tick (100 ms per tick)).
There's a lot of other small changes that are hard to quantify - such as the HQ system being a lot more performant - but overall the game should be smoother and have less stuttering. For a complete list of current and future changes with regard to performance, see this topic.