I admit that the FJC is "hamstrung" by its concept. With that said, it still does very well and does compete with the Jeep market. Maybe its maximum potential is limited but it is still quite competent and capable in relation to "most" Jeeps out there.
I just drove mine over 8300 miles, doing Rubithon, trails in CA and AZ, Moab (Moab Rim, Hells Revenge, Poison Spider to name a few) and hitting the relatively tame but majestic trails in Ouray, then drove it back home. The only damage that it incurred was to my wallet, sucking gas like big bore V8. I couldn't ask for a more reliable and capable off-road vehicle that has taken on most everything I've laid in front of it.
Will I be sad if Toyota discontinues it, not really. Mine is way beyond collector status (though I still have all the stock parts I took off) so that is off the table. My issue will be with the availability of continued support by the aftermarket companies for parts and improvements. Once its "official", resources to develop more parts will stop and the companies will be looking for another market to capture.
Yet, being one who thrives on trying to be as "unique" as possible, mine will have to stay in the stable for a long time coming...