I admire the joobi's products. I am using jnews and acajoom for many years and for many websites (9 plus and pro versions). The scheduler for big lists with many subscribers in the solution for any serve'r limitation.
Congratulations to the support team of Joobi (especially Diego), who are available to fix and support any issue appears in your Joomla.
I will use it again and again, and i will surelly not change it.