I used Ample Power for twelve years and was satisfied with its performace. The only complant I had was when the total battery hours went to 10,000 the unit needed to be reset. I'd stress alittle until I remembered.
I use a Victron BMV-602 and like it a lot. Monitors two battery banks (house and start). More capabilities than I'll ever use (or need). You can even have it store battery use history and transfer it to your laptop to draw graphs in Excel (I've never done this - but it's a cool idea.)
I have a feeling that "Do you want to see some graphs of my amp hour usage?" would not be a great ice breaker at the bar
I agree with Carl that the Victron is close to perfect. In fact, I replaced my Link2000 with the Victron so if you like the Xantrex better and you're in my neighborhood, see my ad in the ads forum ;-)