So Jamie just announced the new Liferay 7.1 Community Beta Program here: https://community.liferay.com/news/liferay-7-1-community-beta-program/
I recommend everyone who has working code in Liferay 7.0 or Liferay DXP should join the 7.1 beta sooner rather than later.
Why? Well, mostly because Liferay's engineering team is focused on the 7.1 release, so anything that you find in beta, well that will be something that they will want to fix before release. Without those bug reports, some incompatibility that you encounter later on falls under the regular release process and that will only work against your release schedule.
Let's say, for example, that you have spent time building out a comprehensive audit solution for your Liferay 7.0/DXP environment where you have a slew of model listeners and a custom output mechanism to route the audit details to an ElasticSearch instance that you report on using Kibana. You've got a decent investment in your auditing solution, one that you plan on leveraging in 7.1 on.
You're basically looking at two choices. Choice #1 is to do nothing; wait for the official 7.1 GA to come out and for your organization to decide it is time to consider an update to 7.1. Now I can't predict what might be part of 7.1, but let's argue that it has one or more bugs related to the audit mechanisms. Perhaps the model listeners registration has changed or the audit messages are broken or the output mechanism isn't invoked consistently, ... I don't know, some sort of bug that maybe could have been caught sooner but ended up getting by. But now that you're looking at the upgrade, you've found the bug and want to report it. That's fine, Liferay wants you to report bugs, but at the time you've found it 7.1 is out and fixing the bug ends up becoming part of the release process.
Choice #2 is to join the Beta program. Now you dedicate a little bit of time to test your code under 7.1 before it goes out and you find and report the issue. Now Liferay has this list of things that they want to knock out for the first GA, so your report becomes one of many that Liferay really wants to deal with for a solid initial release. Your bug gets dealt with before it can impact your own upgrade schedule, and this actually helps you from the early reporting.
So please, please, please sign up for the 7.1 beta program.
Get the 7.1 beta and beat on it as much as you can.
Run the DB upgrade against your current database. Update and deploy your custom modules, make sure features, functionality and APIs are still there that you depend on. Point your load test tool at your instance and see if you have a measurable difference in performance or capacity vs your current environment.
Just bring it. Find and report the problems.
Together we can make the next release one of the best ever, all that's missing is you.