[RWD version 1 ] My research into these mountains indicated that most folks set off from the Lough Derg side and venture "out and back" to Moylussa and in some cases as far as Cragnamurragh. (See for example Onzy's Track 2127). The fact that Gribbon highlights this route in the County Tops book inevitably brings even more "hordes from the East".
Could there be another way? A way that would be more efficient both horizontally and vertically? And a tad less travelled (by walkers at least - the quads and the motor bikes are a different matter)?
csd pretty much showed the way a long time ago in Track 861 but stopped mysteriously in the broad saddle between the two Arderins. (You can see that he turned left and right but then turned back! Why? Maybe he'd already "done" the Arderins?). Wicklore spelled out the answer in his much starred Mountain Comment on Glenvagalliagh. He explains that there is easy access to the two Arderins from Glenvagalliagh and that's the route I chose.
You travel along the road from Killaloe towards Kilbane, or vice versa, until you reach the forest road heading north to Glenvagalliagh (R6395472575) which is almost the highest point on that road. What you do next depends on you and your vehicle. I brought "the Ham" (the name given by our children to the family's 2002 diesel engined Alhambra motor car) further north than csd brought his vehicle . The road was passable with slow careful driving. But it might not be everyone's cup of tea. If you love your car more than you love your legs, you may wish to abandon it near the forest entrance.
The bonus of driving as far as I did was that I did not have far to go to the summit with only modest ascent involved! And there was a wide opening at a sort of junction where I could safely park (with room for a total of two maybe three cars: R64285 73349)
Yes there were electric fences all over the place, and abundant evidence that quads had buzzed about, but the luxury of the short hop up to the Arderins in the dawn light, meant that for once I could simply enjoy the walk rather than fretting about deadlines. (I had snuck out of the house shortly after 4am to get down to Clare, but I needed to be home for Sunday lunch).
I will say what I have to say about the mountains elsewhere. But I was very happy about the route I followed. Whether the same might be said if I had to compete with quads during a busy weekend is a different question. Another way of looking at it is that the quads and motorbikes are simply a hazard of the territory: no matter which route you follow you'll encounter them eventually (unless you are prepared to get out of bed early).

Compare the Statistics
Onzy's Track 2127: 15k with just over 600 metres of ascent
Wicklore's Route (i.e. this route): Circa 10k with only 300 metres of ascent.
It is a testament to the fitness and determination of Onzy that he completed his task in a mere 3 hours 30 minutes. It might take the rest of you longer.

PS I was careful to visit the three possible tops of Moylussa primarily out of concern that some future re-measurement of the plateau by jackill or some other engineer might result in a retrospective cancellation of my little achievement. But there was a bonus involved because the views were exceptional along the edge of the plateau and the little extra effort was well rewarded