Tamron 16-300 vs. Pan. FZ200

I will be posting this in the Panasonic section also as it really is a crossover question!

I have the Canon T4i with the absolutely superb 18-135 lens. However, I miss and would like to have more "reach".

I was considering the new Tamron 16-300. With the discussion about the new FZ1000 and the subsequent comments by those who have and still swear by their FZ200's I now am trying to figure out what makes the most sense.

I would like to be able to carry just one lens when I travel with the Canon but am concerned about the Tamron's low light/without flash capabilities. For me that would most often be inside museums, churches/cathedrals, and the occasional exterior PM shots. While the 18-135 doesn't have the reach, its low light capabilities are quite good.

I also do both static display and flying airshows whenever possible along with landscape and architecture and lots of Fall foliage shots.

The new Tamron is currently priced at $629. and I can get a lightly used/new FZ200 in the $389-$449 range.

My question is should I go ahead and get the Tamron and keep the Canon or (considering the picture taking criteria above) or would I be satisfied with the results from the FZ200 to possibly sell the Canon or take both on my trips and excursions?

I have had two "superzooms" (Sony DSC HS2 and Fuji HS10). The Sony was a really impressive camera for its day and the Fuji did well outside for buildings and landscapes but was a real "crapshoot" when taking indoor photos without flash. Its airshow shots ranged from "so-so" to pretty decent at times with the evf being a real limiting factor for that specific usage.

With the debut of FZ1000, it looks doubtful that Panny will directly replace the 200 but, who knows?

Constructive comments and experienced advice greatly appreciated.

Thanks in advance.