The only down side I have experienced is the price volatility of Bitcoin. This has a huge effect on the business, because you need cash to run the business. Do you convert to fiat immediately or do you hodl the crypto payments you receive? If you choose the latter, how do you keep record of your actual profits?
What is the average percentage of customers you have that pay with Bitcoin and other cryptocurrencies?
If that number is significant you could convert one part of your coins to fiat currency, but you keep other part in Bitcoin.
This way you could save a lot on fees that could be much higher if you constantly convert BTC to Fiat.
In case if only a smaller percentage of your customers pays with Bitcoin, than I would just hold Bitcoin at least few years before selling.