I relish chasing at night, both desert and Plains. I love being alone on the road with the storm, with not a soul around. I can really concentrate and be productive, taking my best pictures between midnight and 3am. I like the way Plains structure looks at night too (although it is more dangerous and you have to see the radar, that eerie feeling that you know something is out there and could be close is nothing to play around with).
Photography-wise, even out in the country there might be annoying air traffic that can get in the pictures, that problem diminishes as well after 2am. During summer monsoon, the desert works on a reverse clock. Plants and animals sleep in the heat of the day, and come alive at night. Cactus flowers also bloom at night. It is nice to see all the wildlife running around, and when the moon is full, you can see everything in the desert, the moon is so bright (like this picture, people think it is the sun but it is actually the moon
http://www.lightninglady.com/) There are also a lot fewer people around, which is a huge plus. Earlier in the night some are out drinking and shooting just causing trouble, and after 2am, that problem sharply declines as well.
Have always chased at night, will always chase at night. Daytime in the plains is great too of course, but the icing comes at night, especially if there is some highly electrical MCS stuff wandering about producing great lightning. A typical desert monsoon chase (for me) is only done at night, from about 7pm-3am.