Hard decision:
Office is a generally small map and when there is almost a full server, T's suffer from blocking a lot. With no block, a full server would be better with no_block. But I'd have to say no, because people tend not to "try" to block you, and you can always jump over them. Blocking has never been too much of a problem for me so I say keep players solid.
I went to play on another server for a few minutes earlier today, had no block on cs_office (and AWPs too, but that's another story).
There's nothing more frustrating (or annoying) than your opponent running through you. Even if you manage to turn around and kill him, it's pretty lame...
Actually, I think the no-block mod makes knifing easier, just today I had several successes because I ran through an enemy that was firing at me and ended up stabbing him in the back.. (spy on TF2 anyone?)
However, I absolutely hate it for two reasons
1)You cant stand on people's heads/stack up
2)It feels creepy when you're running in someone.. like you're a ghost or something.
No block was added because unlike dust office only has 16 spawns per team so if there are more that 32 players people start spawning inside each other and getting stuck. And we had 40+ on the server last night so it got added
Im not going to have a server full of people trying to wiggle out of each other to play the game. Thats just foolish. When i can add more spawns to the map, i will. for now this is the way it stays.