Now please understand that i'm coming at this from a competition player's viewpoint rather than a historical one ...
Why would anyone chose Dragoons as an option (say one Support choice), they're Reliable, Experienced, Pursuit when you can take Light Cavalry incl Hussars which are Valiant etc and Uhlans which match the Dragoons and have Lance.
Both have HA and Cossacks of course.
There's a strong argument for taking Cuirass over Dragoons too.
I'm not a WAAC kind of guy but i've met plenty who are on the competition circuits in the UK. I tend to avoid that kind of competition if i can. However, there will always be those who cherry-pick the best units.
Now before i get shot down in flames, i should mention that i've just ordered a 2nd unit of Dragoons for my Russians.
Thanks
Darren