Just sold my 3 month old bicycle after posting an ad yesterday. Im surprised at how quick OLX could get! I havent bought anything from there so I dont know about that, but about selling, I repeat, its a good website. And as far as Ive heard most of the users of OLX are people genuinely interested in buying and selling.
The website is quick, you can edit your ads after youve posted it too. Options to put up products photos are up as well. Not much time is taken for your ad to get published after youve submitted it.