Is it worth it? Well depends on your type of camping, but I don't hook up to power when I go away so rely on solar charging the batteries during the day so I can use after dark.
How effective is it? Well I use kit from a Dutch company called Victron Energy and they make possibly the best equipment available for off-grid use (campers and boats represent very small-scale installations to them). I also installed a Raspberry Pi computer running Victrons 'Venus GX' software that lets me log my Solar and Battery use constantly (it takes a snapshot every minute and sends it to an Internet portal)
So this is a graph of my consumption for 24hrs and shows where the power that is being consumed is coming from (solar or battery) Screenshot_20180519-084614 by David, on Flickr
And for the same time period, showing what the solar has harvested and how it is being used (directly, or going to recharge the battery bank) Screenshot_20180519-084637 by David, on Flickr You might notice that the solar dips around lunchtime, just when you expect it to be peaking? that is because the batteries are full and the little blue section above the beige bar is a maintentance (float) charge. If the batteries were more depleted or in use at that time, the bars would be a lot higher.
Interesting. Also important to understand what is going on, as otherwise one can suspect a fault. When we are away in Europe, most sites has electricity, so have no issue. When we are away in the UK, it is mostly weekends, and a charges battery will last more than that (it is 'summer'... more daylight). But this is for a caravan. MH might be diffetent (usage).
Charlie - it is pity you do not use the MH, but if you don't there is no point of holding it.