I find the overall mechanic of zeds constantly sprinting on HOE to be very hectic compared to the first game.
Due to fast moving zeds and very wobbly moving animations on zeds, the players can't really ever hold out in one spot. They either have to be on the move constantly, or do a cheese tactic like zerk walling.
Other mechanics like how the doors function in this game also contribute to not being able to hold out in one spot as opposed to staying on the move. These changes include doors having health in addition to weld integrity, and doors not respawning after each wave. If doors respawned and the health was at least visible, it would make doors a lot more useful in holding one spot.
There are various reasons that I like holding out in one spot over staying on the move, but one of the main reasons that being on the move constantly can be frustrating in KF2 has to do with map design. Due to zeds moving very quickly, and having little time to make decisions or clear a path to move through, there are many things that ruin otherwise good maps in KF2. These things mostly include tight hallways, dead-ends, areas that look like you can go but cant (limited to custom maps), and railings that are either too high to jump over, or just high enough that they take a try or 2 to get over (knockback on zeds makes it harder to jump over things on the run).
Another reason why I don't like sprint in KF2 is that it doesn't have much thought involved with it. When you're moving, you simple always hold down shift, no questions asked, where as other tactical shooters such as CSGO have accuracy penalties for moving. In not saying to make you miss all your shots while running KF2, I'm just saying that on players, needing to constantly sprint is just kind of weird to me. I'd rather it be a decision making thing or just not have it at all. Something like "you move much faster, but there's like 1 second downtime between sprinting and shooting, would make it feel a lot better to me at least.
Also perks that have to constantly reload like support and demo often get surrounded a lot faster than other perks on higher difficulties because the game revolves so much around constantly sprinting, that perks that can't do that (because you can't reload while sprinting) end up getting caught out really easily, which is most likely one of the main reasons that most people I know that play HOE just think support is bad.
Aside from movement mechanics, I liked it better in KF1 where the Fleshpound could 1 hit kill players on HOE, but could be taken down more reliably by Demo and Sharpshooter. With the railgun this is now possible, but demo still can't really do it with 6 people on HOE.