Q: How reliable is the tracking in GetSales for messages marked as "opened," especially when sending messages directly on LinkedIn?
The open rate for LinkedIn messages is tracked accurately if the corresponding settings are enabled on the sender's LinkedIn profile. By default, all LinkedIn users have the "read" notifications on. In GetSales the LinkedIn message open rate depends on two factors: 1) your sender's account has the read receipts on - if it's disabled, the open rate will be 0; 2) your leads have the read receipts on. The read receipts can be managed in your LinkedIn settings under Data Privacy > Read receipts and typing indicators.
Q: When viewing "Messages Replied" in the dashboard analytics, does it count every single answer or only the first reply?
It counts one contact who replied. If a contact replied several times during the period you're viewing on the dashboard, it will show as one message replied.