I just want to say up front that I do not own an LWRCi rifle or upper. I do, however, own several piston variants (PWS, LMT, AA). I purchased a Bren 805 with the LEO/MIL discount directly through CZ-USA, and I have to say that I am impressed with it. While I own several polymer pistols, I wasn't sure how I would feel about a rifle with a polymer lower. I actually like the damn thing... a LOT. As pointed out above, the Bren is a smooth shooter. I run my support hand out far enough as to not interfere with the charging handle. Aside from the charging handle the rest of the Bren controls are very similar to the AR platform. A simple adjustment to the AR manual of arms is all that is needed to operate the rifle effectively. Accuracy wise it is "good enough" in my book. I have precision built rifles that fill the precision role, unfortunately the Bren does not currently have the aftermarket system to build one out as fancy as an AR.
I would still like to get my hands on an LWRCi, and may do that in the near future. However my safe has seen a bit of AR-over saturation and needed some different blood in the mix. If I had to make the decision between the two, I would honestly look at price first as I feel both are a quality product.
Keep us updated as to your decision and purchase!