@bigdodgetrain
I have experimented with an enhanced antenna, but it was unsuccessful. Eric says he is running among four rooms of 400 sq. ft. separated by three interior walls. I am running on approximately 7,000 sq. ft. separated by three exterior walls one of which is concrete and blocked by a large Red Cedar and Douglas Fir both of which are over four feet in diameter. I do use an an additional antenna though for DCS which adds about 50 feet of range.
As for the new 990 bases, Mike Reagan indicated that some electronic components would be more robust so Lionel wouldn't have to repeat the repair problems they have incurred with some of the current batch they have in circulation. I've already had to buy a replacement on the forum because one failed and the retailer couldn't repair it. You'll remember Lionel service was shut down for six months.
So that's why I run with two bases and plan to acquire a new one for backup. I'm well aware there are no new capabilities. Hopefully more reliability though.