Buggy. Linkedin integration often sends the same message 3 or 4 times to the same person and I've received complains.
Stats are also not accurate, It was showing 54 email sent from my inbox in the current/last week when in fact the last ones have been sent 2 weeks ago. Reason being, they count AND HAVE ACCESS TO ALL personal emails as well, not only the ones sent with apollo. this is a big privacy concern for me.
It would be best to use an email account that is only used for this purpose, not your personal work email
Pricing and plan structure is unclear. You feel like not fully aware about what you get in the plan. Just when using certain features you find out you need to upgrade.
Linkeding connection request with customized message doesn't work without Linkedin premium account (not Apollo's responsibility of course but this is absolutely not stated anywhere).
Support team is a bit unresponsive, they reply only to the things they know and regarding the bugs they just make you wait days and give you no actually solution or debugging support.