I'm going to wait for the second one before I decide even though I already bought the first one. I'm still on the fence about that one since the developer jumped ship for a period of time.
The catch with these complex add-ons is that they might pose a problem if you want to upgrade your board in the future. They need to be actively supported by a trustworthy developer. Most boards can't or don't want to wait for months on end before upgrading XF if, however unlikely, the add-on wouldn't be compatible with a future release.
If that happens with other less complex add-ons it's usually no biggy. You have the option to hire someone to write a new one or crowdsource something that does the same thing. Depending on the add-on you might even go ahead without it for a period of time without much grief from the users. But imagine having to disable the classifieds section because you have to upgrade your board. That wouldn't be very popular among the users