I went the sporty's route. I bought the SP-200 about a year ago and I love it. The VOR/LOC display is actually a nice thing to have available. I have used both the VOR and the LOC on the handheld and they both were within 2 degrees of the CDI in the aircraft. In a bind, it would be a nice thing to have. As far as battery life, it just depends on how much you use it. I have replaced my batts once, even then they didn't need it but I wanted fresh batts in there before a long IFR flight. SP-200 is definitely larger than the A23 but I haven't had any problems with the size.
Good luck with your search. The deciding factor for me was the VOR/LOC display and the "last-freq" button.