Anyone who suggests using Panels or Rules on a Drupal site within earshot of me usually gets a similar response. While these modules offer an enormous amount of flexibility, they do it at a cost of both performance and complexity. Rules can be used to do something simple like sending an email to someone when a new node of a specific content type is added, but this can also be achieved with just a few lines of code in a custom module.
Rules and Panels can be good fits if someone who does't know PHP or Drupal's templating system is going to be making changes. However if you are paying a developer to configure Rules or a themer to configure Panels with no intention of letting non-developers make changes, you are probably paying for something that is costing you more in performance, upgrades, and complexity than a custom module or template file would.
While Panels/Display Suite/Context in D7 were huge improvements over the options in D6, they fell (far?) short of actually being user friendly. For presentations at Drupal Austria Meetup, Drupal Dev Days Szeged and DrupalCamp Donetsk, drunomics surveyed users about what layout tools they were using in D7 and what they were looking forward to in D8.
While Panels was the most popular "favorite" D7 module..
... just more than half the respondents were actually looking forward to using it in D8.
While you could question the methodology and sample size of the drunomics survey, it mirrors the antidotal feedback I often get on the topic. While "everyone" is excited about the Twig based improvements in D8, the improvements to the trusty/crusty old Drupal block rates above Panels in what people are looking forward to in D8. Only slightly more than 50% of user plan to do more than "Give Panels a Try" in D8. Context and Display Suite actually have a measurable number of negative responses. These are modules people dislike so much they hope to never use them again in D8.
Why does this matter? Because the "drop" is always moving.
While most people are able to wrap their heads around editing the body content of a node in Drupal, managing layouts in Drupal can be overwhelming. WordPress is MUCH easier. Why does a block show up for one user, but not another? Where is that content coming from? Oh, it's a View driven block so I need to find the nodes being displayed and edit those. Even experienced developers can have WTF moments when trying to update the layout of a "page" in Drupal.
So what would a layout tool that was inspired by what worked well in D7 and rewritten with a non-developer user as the target user look like? Probably a lot like the New Layout Tool for Backdrop @quicksketch just recorded a screencast for...
Is CMDrupal moving to Backdrop? That's something the organization's funding the development will need to decide. When I look at the cost of doing complete rewrites for D8 vs. incremental updates to the more D7-like Backdrop CMS and what we'd get from Backdrop vs. D8, it's really hard to make the case to upgrade to D8. Of course we can just continue using D7, but there is will be increasingly less effort going into improving D7 and it will continue to fall further behind in what users expect when editing content on the web.
When I look at Backdrop's Philosophy and the track record the project's leadership team have had in making complicated functionality easier (ie. WebForm vs. CCK), it looks like Backdrop may end up being a better fit for community media groups than D8. It's possible that Backdrop will hit the sweat spot of being a more flexible framework than WordPress while being easier for non-developers to use and understand than Drupal. Since neither project has reached a beta, it's still too soon to tell... but it's not too soon to consider the upgradability when funding improvements.
While Rules was recently able to raise ~$16,000USD to complete Milestone 1 of the D7 to D8 upgrade, I think a large number of people who contributed are going to be disappointed when they realize that it won't be until Milestone 2 that Rules team will "make sure that the Rules APIs are ready early enough, so that all other contributed modules that get ported to Drupal 8 can port their Rules integrations". Milestone 2 requires another $64,000USD in funding.
So if you have 10 minutes, take a look at the screencast on YouTube, if you have more than a few minutes, try installing Backdrop and take the new Layout tool for a spin yourself, and if you are investing in development, try to avoid Panels and Rules if possible.