I'm not sure about AI Writers (I don't use any), but when it comes to AI Re-writers, I have a personal fave list:
JesperAI was not worth the price it demanded, due mainly to the 20k/month word limit on the cheaper plan and the lack of refinement at the higher price levels. At its best, it failed to impress me, and at its worst, it made me laugh. I'm not sure if they finally taught the miserable little thing to distinguish between "shit" and "cheat" since it was several months ago.
Quillbot, on the other hand, was - and continues to be - a fantastic re-writing tool, even in its free version! Whatever you throw at it, it manages to be both quick and effective at work. I have yet to try the premium subscription, but based on what I've seen so far, it is definitely a must-have now.
Grammarly is another must-have tool for keeping your texts neat and ready to publish. I'm baffled by how many blogs fail the spelling and grammar checkpoints; I've seen enough basic grammatical mistakes to wonder if they were written by a crappy AI or a preschooler. Grammarly Free is enough to fix any errors, but the Premium package is where it stands out from the crowd: a built-in citation tool, a true, reliable plagiarism checker, and one of the better integrations between writing programs (Google Docs, Excel) I've seen.
TL;DR: Before you jump on the cheapest boat available, make sure you really need an AI Writing tool. Those free tools listed above are sufficient to aid you in writing a reasonable number of blog posts in a decent amount of time, and you can use them all together and have them check each other's work to further improve quality (not quantity).
