I sold a Mac Mini M1 to them about 2 weeks ago, I can only recommend for selling on my experience. I got about 10% less than I expected if I went Ebay, with no costs or problems... So I am happy with that. Sold as Grade B - opened and no box, but otherwise perfect and received the money 3 working days after I took it to the local store into my bank account. A voucher would have offered about 20% more 'value' but I didn't want to buy anything from them.
Good way to sell unwanted equipment with no issues as long as you are happy with the price offered and realistic about the condition.