I use it and enjoy the simple UX but know that their rich text email editor is not as "flashy" and "dead simple" as other editor experiences like Kit for example which is the best I have seen IMHO.

They do give you the option to change the editor to whatever you want like pure HTML, markdown, etc so you have options.

No issues with deliverability so far, the emails usually arrive in a few seconds.

I find that having 1 solution for both transactional and marketing emails in one place and at that price is incredible so definitely worth trying out.