Options are always good. But maybe I'm the only person here who isn't excited by this configuration. I don't know the official specs, but it seems as if the weight savings are only incremental. I'd rather have a pistol grip. Then, the nail in the coffin for me is you take an average accuracy gun, give it a thinner barrel and make it less accurate. Not for me.
I certainly agree with the philosophy that rifles should be accurate. Normally, I'd be there with you on this, but:
1) In the video, they mentioned that the lower can be swapped for the pistol grip if you like. Kel-Tec cleverly made an inconsequential and indestructible part the serialized part on the RDB for maximum configuration and maintenance.
2) The boys didn't seem to be having much trouble getting hits in the video. Generally, if they could see it, they could hit it. It's not a match rifle but the pencil barrel didn't seem to adversely impact the accuracy compared to the heavier barrel RDB. If so, I suspect the accuracy limits are imposed by variations in chambering and barrel flex with the gas system, and maybe similar issues. Even if there is a slight degradation in accuracy, the RDB Survival is clearly accurate enough for most people's "Philosophy Of Use", to borrow a nutnfancy term.
I'm a fan of pistol grips on rifles like this, but honestly, I'd probably buy the Buck Rogers space gun version of the RDB if it wasn't for the fact that Kel-Tec did this so politicians would allow them to sell in California and that offends my sensibilities.