Mixing ram ok in real world usage?

I used to have 16gb ram, went down to 8 after putting 8 in the Phenom x6 pc, but at times feel cramped with 8gb with multitasking chrome tabs and gaming,etc. I notice my Corsair Vengeance is a little pricey compared to some cheap Crucial or G.Skill stuff on newegg, would that be ok to nab a 8gb stick? I currently have two 4gb sticks for a total of 8gb. I'd get the same voltage and timings of course.

When I had 16gb ram it was actually g skill mixed with my corsair, but same voltage and timings 9-9-9-24 and 1.5v. I never had problems, but people online seem to swear it's very bad to mix ram? Maybe it's an old wives tale from the old days and people were mixing different timings and voltages?


tbh I used different timing and voltage ram in two different older desktops sitting around and they never crashed or anything.

or I suppose if mixing different companies ram is truly "bad" I could get a single 8gb Vengeance stick if it really came down to it, but then that would put me in single channel mode? At that point I'd have two 4gb sticks and a single 8gb stick.
 
it's possible that you can get it to work, it's also possible that it would cause issues. It's really a toss up. You could try manipulating the timings to try and get them to work together, but it won't work as well as just getting a new kit of 2x8gb. If you have that money of course.