@Tudorleuu:
Request a Mod---
I'm not so sure about stuff like 1x5 and 1x7 bricks. Things will get really messy if people keep requesting new odd-sizes.
They're not really
needed, since those situations can be dealt with.
By "extremely useful" I mean add-ons like the vertical pole bricks. Some details aren't possible without them.
Same thing for the round corner bricks, except they're based on LEGO bricks. So they're useful AND LEGO-like.
In my opinion, it's better to have the extra bricks and not use them than to need them and not have them.
Edit: The server already uses a few brick add-ons, so compatibility is already out the window. (If you wanted to load the save on your own.)
It's pretty much down to preference and what Wedge is willing to do.