The clip+ does have a slightly longer battery life due to the smaller screen and e type of screen display. My clip+ batty lasted about 1.5 to 2 weeks. The clip zip has a slightly shorter battery life as mentioned above. But there are some tricks to increase its length, 1) put it on a lower brightness setting 2) set the screen to turn off sooner than later. The real question you have to ask is how long will you be traveling and how frequent are the opportunities you will have access to an outlet. Either one is a good buy.
I dont think the battery life is that bad. But it depends how much listening you will be doing on your traveling, and how long you will be traveling. I cant say if you should go with the Clip+ or not b/c I dont own one. BUT you could get one of those wall outlet plugs that you can plug in a USB cable and then you can charge your Clip Zip when your on longer vacations.
I'm on my fifth Sansa and have had both the Clip+ and the Zip Clip. I've dropped them in the Pool and some just stopped working so I go through one a year. YES the battery life is shorter. Also be sure you condition the battery. My current Zip Clip gets about 4 hours before the battery drains. However, (you knew there was a but coming) the Zip Clip does have much better reception for FM radio if you use that function. The Zip Clip feels cheaper and don't count on the clip, it will break. They have done nothing to improve on that. With that said I still like them. They are small, can hold plenty of books/music and I can listen to the radio. Find that on any other small mp3 player...unless you want to pay the big bucks for an apple product. I figure for $40 a year, yeah it's worth it.