Hey there... I own one.
Is it cool? Yes. Is it fun? Yes. Is it worth it? I dunno...
Here's why: each magazine can hold 30 BBs. On 6 round burst @ 600 RPM , well .. you do the math. It goes quick. You then need to reload and finish off the CO2 which on the second run of 30 starts to drop off quickly.
You really need spare mags (which are hard to find and a bit pricey @ 40-50 bucks).
There are tons of mods out there. Everything from a F/A 1200RPM board to adding a nitro High pressure tank like on airsoft guns. Barrel kits are available as well.
I currently have installed a long barrel which really boosted the FPS and gave it the SMG look I was going for.
By the way - the Drozd is loud. Not too loud but enough to get the neighbors to look over if you are in the back yard blasting squirrels or cans or bottles or anything else you can imagine shooting up.
All things said and done, I don't regret the purchase but it really wasn't my smartest either. That same 400 could have easily bought an upper for an AR, a new Handgun, a boatload of ammo , etc.... However, none of those items can be used in the garage or the backyard like the Drozd can
If you decide to go for it make sure you only use the high grade steel bbs. The cheaper BBs or Lead BBs will deform in the barrel and jam. Major PITA to get out.
Bottom line: if you have that kind of cash to burn, go for it.