You can easily convert your falcons to
WS. There was an article on how to do a long time ago in
WD. You don't even really need the rear add-on section. Converting the turret and adding on the energy field will be enough to make it easily recognized.
For YEARS the
WS was in our Codex, with no
WS model available. Then, finally
FW made a resin conversion kit for them, if you were willing to hand out the cash for it. Then, finally...and literally, several years later,
GW released a
WS model.
Several of us still have our home-made conversions from back in the day, and they are fine to use. They are a
GW based converted model, so they are even legal for tourney use. I actually get alot of compliments on mine