I actually misunderstood, I thought you had meant you were getting feedback from SaleHoo members. We can't follow up on supplier complaints from other forums anyway because we aren't able to validate that feedback. That said, issues like account fees and customer service negatives are quite common to find about all suppliers, but they aren't issues we would be able to act on even if those issues were raised by our community.
I think it's absolutely valid to take feedback seriously, no matter where you read it. The only thing I would say regarding suppliers that charge account fees, don't judge them on that point in isolation. Many do, as soon as they see a fee attached they take a very negative approach to the supplier straight away. No one likes paying those sorts of fees, but I think you have to judge a supplier in regards to the total value they provide. Product prices, bonus scheme opportunitiesm shipping times and so on.
Some times even with an account fee, the supplier can still be a better choice over a supplier with no fees.
Customer service itself is something that seems to be a serious issue among most dropship suppliers for some reason. I can understand that they get swamped with inquiries, but I'll never understand why they don't treat all inquiries as priorities. One tip I would suggest, make sure the supplier has a phone contact option.
If you ever need to get a problem resolved in a hurry, the last thing you want to be doing is relying on email alone. You need a means to contact them and have a resolution in place asap.