Sorry but I am not buying the current spawn idea.
On a competitive 5x5 scale this means to me that:
It is very possible that certain objectives will be accomplished only by luck on attackers side - say, while planting at the wall you need ALL enemies to be killed at some point to be able to plant. The only chance to get this under current system is when attackers manage to kill all defenders almost simultaneously and that also combined with the attacking engie surviving this onslaught. Because if the defenders are dying one by one with an interval of 3-4 seconds, you will always have someone on defense because the first killed ones will be constantly returning.In theory the indivisual returning defenders will only need to throw a grenade one by one to gib the engineer near the plant area, in order to defend the objective, tuning it into a grenade train. This is of course an extreme, almost absurd example but it is possible.
On the other hand, the real fighting turns in reality from 5x5 into constant 5x6 or 5x7 because in most cases it takes time to kill all the defense. And while you team takes time to do it, the defense gets constantly resupplied. I don’t see how that can be good. The tactic “kill them all to do the obj” loses all sense in the current layout. For the pub it will probably not matter much, but for SW… nein!
Also RuneForce got that thing well put:
One thing I find particular annoying on the defense: if you die and get revived shortly before the timer reaches respawn and then die again shortly afterwards, you have to wait the full time again. I would like to see that time shortened (if you got revived X seconds ago and die again.)

(on purpose, I suppose.)