Firstly, I agree completely thats it great being able to keep one crawler/runner left at the end of the round while you gear up and prepare yourselves (I wouldn't have been able to do Richtofens EE by round 6 otherwise), but perhaps this is what Treyarch wants to move away from?
Less emphasise on what round your upto (round just being an indication of how fast/many zombies there are) and more about zombies kills.
With zombies CONSTANTLY spawning, spamming the box at the end of a round wont be possible - each weapon recieved will be a gift and have to made use of.
Travelling from one side of Tranzit to another on-foot will be more of a challenge and not just tedious time wasting. The bus suddenly has more value.
You'll have to watch each other backs while you buy perks, and I'de hate to try and pack-a-punch in that narrow corridor knowing zombies will be flowing from the windows and vault entry whilst trying to do so.
It sounds like there's lots of issues with this new system, but it sounds like it could be alot more exciting to me.