As others have said and lots of info on the LN Eng. site.
Use a recommended installer when possible so they do a pre-qualification on your car, to see if it is even fit for a new IMS. If you have the money, do the IMS solution.
If there is already debris in the engine and the current IMS is failing, it is already too late.
I went with the Single Row even though at the garage I use, (apart from LN and Flat6 Innov) was the only recommended 'Solution' installer at the time.
The reason was, by the time I will need another IMS changed out for another piece of mind, I would surely need a new clutch or 2 by then. Also, IMS is not the only thing that can cause catastrophic engine failure on the M96. Can always spend the money on another water pump for example
It really depends on you, how you see your car and usage