I was flying into Austin from Corpus that same day, and had to hold 20 minutes while the storm moved over Bergstrom. Kinda crazy, I haven't had to hold for a couple years. They shut down arrivals for everybody after a 737 and a Lear both got some bad windshear on final.
They shut down Kittie Hill right after I moved down there. I was pretty disappointed, I thought I'd have a grass strip five miles down the road from me, and then only got to visit it twice before it got sold.
Where did you end up moving your Navion to? Unless you don't want to violate persec, which I understand!
ETA- And another big +1 to getting a new GPS. I run a Garmin 295 in the RV, but only because I have an iPad as well! Get a Garmin 696 and the XM subscription. You'll have NexRAD, XM Radio, XM Metars and Wx, and all kinds of goodies. I wouldn't fly a cross-country without it, XM weather is a game-changer.
In my opinion, It's better than on-board radar, since you get the big picture. In the jets we have both, but if I had to pick one, I'd pick it.