Requires a lot of macros to automatize simple operations
Unable to switch selection mode by dragging mouse from left to right and from right to left.
Unable to lock the parts - this is huge issue that might cause a big problem! user can accidentally move the part in the assembly (when working at the top level) just for tiny bit and never catch it! and if you try not to work at the top level then good luck with pulling dimensions between different sub parts!
It uses its own macro language instead of normal VB or C or whatever the industry standard is - I think it is a con.
In summary we all almost hate Drafting here and will be switching to something else, especially considering that there are many other 2D CAD packages given away for free these days and PTC still charges a lot of money for their crappy unfinished product.