I read the RV daily Mag Article when that issue came out and was somewhat surprised at the 10AH of output from 450W of panel. However, I have said previously a number of times, you get what you pay for and equally how it is used. I might also add that there are quite a few vendors out there that have little understanding of what they sell. The sale is more important than "if it will do what is said it will". Contrary to that there are a few that do know their stuff, the difficulty is finding them.
In comparison to the 450W of panels in the article, I have 2 x 100W panels on my van roof and I try to park it where it is in full sun. (To qualify, I detect in winter time in VIC, so not too worried about heat

). On a dull overcast day, I've monitored 12-13 amps going in to my battery, which is what I would expect from these panels. Parking any van in a shaded area with panels on the roof and expecting them to do their job is wishful thinking to say the least.
I'm rarely at the van during the day as I'm out detecting, but on rainy days or "I'm running out of jocks n socks, gotta do some washing days", I am able to see what is happening. I regularly use, as I've said in other posts, between 30-40 AH from the 130AH battery. (TV, lights, diesel heater, pump, charging all the other gear.)
I know how much I use (20-30% of capacity), that the battery is close to 97% fully charged by 1-2 pm depending on the weather and full by the time I return from prospecting. Although I use a genny for other things, I have spent some time where gennys were not allowed. After 4 days, again in crappy weather and on solar only, I was showing 99% full. (before using power on the 4th day).
We all have differing power needs, different equipment, budgets and knowledge. Although these articles mean well, they can mislead, especially if the reader is not technically experienced.