I dont have the RCBS.. but I do have the Hornady Lock-n-Load auto charger..
I researched several options before I bought the Hornady.. I found that pretty much all of them have the same quirks and issues related to performance and the recommendations for fixing those quirks (like the drinking straw trick
@Bert01 mentions above) were pretty much the same as well...
auto chargers arent perfect.. until you step into the pro grade gear most of them are notorious for throwing over charges by a few .01's of a gn every few throws.. but this is pretty easy to overcome just by setting the thing up to run a little slower (which is still WAY faster than hand measuring and weighing each charge).. and most are only reasonably accurate when it comes to weighing the charge (if you take the load off the scale and put it on a more precise scale you might find that your 46gn charge is actually 45.9 or 46.1, etc).. but.. for loading hunting grade or "range" ammo.. I find that mine works wonderfully..
If I were loading for a .25 MOA rifle.. or trying to compete in PRS, etc.. the chargemaster or the lock-n-load wouldnt be my first choice.. but.. for loading 375 H&H thats going to be shot inside 300 yards at game animals.. or 308 at 300 yards, etc.. etc.. Its been a great investment for me..
Using a single stage press for everything and the auto charger.. I can easily load 50 rounds of any rifle caliber cartridge in less than 45 minutes.. and thats taking my time, taking it easy, etc..
That never was a possibility for me when I was hand dispensing and weighing each charge on a little separate digital scale, then using a trickle charger to finish off the load, etc..
The only reason I went with the Hornady over the RCBS was.. at the time I was purchasing, I found the Hornady option on sale for about $125 less than the RCBS option.. From all of the reviews I watched, etc.. I dont think quality or performance is really very different between the two.. whichever one I found cheaper was the one I was going to buy.. so it ended up being the hornaday..