Yeah everything would be 10 times easier with odd numbers but its just... some OCD thing that it just HAS to align with the chunk boundaries on all sides lol.But odd numbers are better.
Building guides are what I use to make all my Mage towers.
And biospheres, and... well you get the idea.
It got one thing going for itself though, the F9 chunk grid can be quite handy for comparing stuff and counting etc
But I must say, one of the most handy tools is probably the Bibliocraft "Tape measure". Easy to measure radius etc.