@ruffsl the impression I’m getting is that if we can find someone interested in long-term maintenance of ROS2 Cartographer, that’s the direction folks want to go. With that said, since Google’s (seemingly) abandoned it for the foreseeable future and the codebase is how it is, I think this is a good entry point the way that gmapping was a good entry point in ROS1: it probably isn’t the best solution, but its here and its well documented. And for the “default” SLAM in ROS I think that’s OK, if folks want something different/better/niche, there are other “non-default” options available as we’re talking about above.
With that said, “impressions” aren’t worth much and we really need to look at this more analytically or at least perform a proper trade study that we can publish along side our decision to justify it. If folks really do care about picking something different/better/niche that should be reflected.
Towards less “impressions” arguments: I can say both from my experience and the experiences of plenty of other robotics professionals in industry ranging from Warehousing (4x), Retail (2x), and libraries (yes, libraries 1x) we all have the same qualms with Cartographer. After dumping independently lots of resources into it, it came out as a non-decision of building a product around. But most people aren’t doing that and even in ROS1 GMapping was sufficient for the vast majority of users. I think the second most important question in making a decision (after is there a long-term maintainer) is who we’re targeting this for and why. That very much so changes what the best “default” should be.
@rgreid I think for now if you have thoughts, you should express them here so they’re documented and we can digest & continue a dialog. This isn’t a decision we’re going to be able to make in a 30 minute lunch break even with everyone together 
. I wouldn’t go too much into the weeds of loose/tight since that’s not really the point, but if you have tangible implementations you can recommend that are “industrial grade” we’re all ears to hear about all the options on the table. At the moment we’re only considering lidar slam, but we’re not opposed to a vision (or a visual component with lidar slam) assuming it is actually robust and comes with an additionally robust localization method over the long haul. If you can provide me an example of one, I’ll throw away all my lidars and happily join the vision camp .