I like expanders over gates a lot of the time.  Gates are good for signals that jump quickly from a low level sound to a much higher level.  Under these conditions they can open and close cleanly.  But when things are happening around the threshold such as ghost tom hits etc, they can chatter.
 
Expanders are smoother and often more sensible.  They have the ability to still really quieten things down between the important stuff but also open when they need to and let even modest things through which sometimes you need.
 
DMG's Expurgate looks impressive in that sense.  It is over $200 AU which is a lot for an expander/gate.
 
 
 
 

You can just do it manually for toms. Cymbals snare and kick get hit too much to bother, but the toms can be done by hand.

For me a gate is something i can use if i can hear it while performing. I never have used a gate after the fact.

Jeff,
 
For a dumb fork like me, can you explain anything more about expander vs gate.
 
Only know how to work gates. The noise gate is the last audio effect that is still in a primitive and unacceptable state of the art.  10 years from now this will not be an issue, but a pain in the chalumbas in the here and now.
 
Advise something better if we got it on the horizon?
 
John

Ok, going to post this as Toneboosters tend to always be forgotten though they are rock solid plugins: https://www.toneboosters.com/tb_trackessentials_v3.html
 

The difference between an expander an a gate is the same as a limiter vs compressor only backwards.
 
In other words, with a gate you get no sound (more or less) until you cross the threshold.
 
With an expander, the sound comes up at a fraction of the normal rate until it hits the threshold. So if the threshold is at 40, the level at -50 would  be reduced according to your ratio. At a 2:1 ration when level is at -50 the sound would be at -60. The sound would decrease at twice the actual below the threshold.
 
A gate is like an inf:1 ratio where once you are below the threshold there is an abrupt cut off. On the off side, this can be tempered with a release, but on the starting side, it's abrupt. It's often used on a hard attack rhythm guitar.
 
This video shows some gates.
https://www.youtube.com/watch?v=gWij_S5kf1g
 

Gates are used a lot for live sound (especially kick).
Played many gigs where I just wish the drummer would damp the kick a little better.  
 
Mixing wise, I'm not a big fan of gates.
If not set "just so"... you can get nasty "chattering" which sounds artificial.
Kick is usually more consistent... and isn't too hard to get the Gate dialed-in.
Snare may be a bit more tricky (depending on the dynamics of the player).
For Toms, as was mentioned, you can edit the tracks manually (toms are usually sparse).
Overheads I wouldn't use a Gate.  Way too much nuance and changes in dynamics...

To simplify the difference between gates and expanders further..
 
A gate starts to open at the threshold.
An expander is fully open by the threshold.

All I know is that nearly every software gate performs better than nearly every hardware gate I ever used.
 
That said, every software gate is still frustratingly fiddly. Up to and including the best one on the market (which would be Pro-G, IMO).

I'm demoing the expurgate and pro-g and so far the expurgate is edging out the pro-g. The frequency adjustments in expurgate allows me to really hone in on the kick better. More tests to come