It's not necessarily noticeable if you only call one wave in early. For example, if you called in the first 5 waves early you could potentially generate enough to build a new turret. It will likely make it a bit tougher but if you can get to wave 47 then a few extra monsters during the early game should be a piece of cake. You're also going to get a better score at the end if you're calling in waves early. Making some good progress with survival. It might feel a bit easier during the first 20 waves but a lot of players were struggling to get that far. All maps should feel a lot more viable now, especially with the extra tower platforms and the cost of building them is going to go down significantly (price still TBC).