I hate them really.

However, there are only a few companies that do what they do.
The first year, they oversold me and tried to force me into a very expensive support plan.
I had to fight for months to get that taken off my invoice.
Fortunately I had not paid the full invoice yet.
They also estimated the number of transactions really high, so don't let them do that to you.
In the end, it works fine with the cart and keeps us from the tax man beating on our door.
Other than our home state of Florida, we have 11 states we met the threshold for collecting.
Many states have set reasonable thresholds, but it's these number of transactions that's the problem with some states.
They will have like a $100k threshold, but also 200 transactions.
We get a number of small orders (under 10 bucks) that forces us to collect in these states where do do not meet the 100k threshold.
It's very frustrating.
In the end, I sleep better knowing I am in compliance, when for several years I was flying under the radar...
Hopefully one day they will simplify it all. There is no way I am willing to sit and file 12 sales tax returns each month manually.
Do not let them upsell you on a bunch of extras you do not need. Support - no need - it works. Keeping track of exemption certificates, not that hard to do manually - I don't recommend using their service for that.
Thanks,
David