I haven't had an issue with getting paid by Reverb, they seem to have their process in order as far as receiving or sending funds. That's been my experience anyway.
My issue with them is that after shipping costs, sales tax, and their percentage being deducted from the selling price- what the seller ultimately receives doesn't reflect what the product is worth. Adding those costs to the price puts the item over market value, making it difficult to sell.
In addition, their Customer Service is not very accessible. It used to be possible to contact an Agent by phone; no longer. It's now either by chat or E-mail.
Of late I end up selling more on Reverb than here, cause I usually can get a higher selling price due to a larger pool.
I also set the price higher than TB, I’ll add $75-$100 shipping fee, and any sales tax the buyer pays and is added. Your fees are not lowered by this. I also find I get a much better deal from shipping fees on Reverb than direct, so it’s not as bad a deal as some make it out to be. IMO.