First of all the Illustator plug-ins Astute Graphics offers are generally speaking great to use. Unfortunately the company behind it makes it hard to really appreciate them. Here's a list of reasons based on my experiences.
1. Extremely hard to get refunds. Many other software vendors offer them with no questions asked policy which makes buying from them safer. Astute has listed terms and conditions on their site that need to met before being eligible for a refund. This kind of behavior makes a company seem unsure of their own products. You might want to go through that list before doing business with them.
2. If you buy plug-ins from Astute Graphics get ready to always be up to date with the latest bought upgrades since they drop support for older versions the second the new one comes out. Ideally you'd always have to be using the latest version of Illustrator and the latest version of Astute plug-ins. If you don't upgrade to the latest plug-in version don't get upset if they stop working when a new Illustator version is released. I just noticed this when a plug-in that worked in Illustrator CC2018 yesterday totally stopped working in CC2019. And yes, it's understandable that Astute won't offer support for older versions of their plug-ins but when you realize they only offer upgrade prices for a month(!) after the new plug-in version comes out you realize you're dealing with a software company that's writing its own rules, and not in a good way.
3. Customer service is terrible. I was basically b-i-t-c-h-e-d at for daring to ask questions they didn't appreciate, mainly for trying to politely get a refund after having misunderstood the Illustrator version the plug-ins I'd bought would work in. (The information was not clearly available on their website, and it's still quite messy.) When you treat your customers rudely you make it clear you don't really appreciate them as your customers, you only want their money this one time. Astute Graphics made it clear they just don't care. Their behavior also made it clear I'd never want to contact their customer support again.
4. Understanding which plug-in versions work in which Illustrator version is complicated, if you're not always up to date with your plug-in upgrades. Yes, once again I realize that it's hard to offer plug-ins for software made by others but still, even installing the plug-ins is messy if you're not using the latest version of Astute plug-ins.
I'm a freelancer and I don't swim in money. I've been buying software since the mid 90s and quite frankly buying from Astute Graphics has been the worst experience during that time. Yes, they make great products but apparently when you think you walk on water you believe you can treat your customers any way you like.
Will I ever buy from them again? Probably but only because they offer one of a kind products. However I most definitely would've already bought more if I knew I was dealing with a company that I know treats me with respect.