Steve, sorry I have not gotten back to you sooner. We did have an Echo charger in our 99 Alpine, and it did a great job. However, the Apex is much different and a lot of power demands. So I can not say if the Echo would be a good or bad choice.
We have had battery charging issues since leaving home now. I bought a new 200A alternator, yet to be installed. Each morning, I am running at 11.9 to 12.3v for an hour before it bumps up to 14.2v. This often occurs after lunch breaks at rest stops. We have a big drain on the chassis batts when dry camping overnight, even if charged up by the gen.
More testing to do
Ed