I recently took a family vacation to China, and decided to rent a MiFi hotspot device so we could all share a cellular internet connection. This is a really great service for travelling internationally in a group. If you split the cost, it's very reasonable, and you don't have to deal with wonky hotel WiFi. It just works everywhere. I went through 3gsolutions and everything worked as expected.
One thing I forgot to take into account though is that when iCloud enabled devices connect through WiFi, they assume they have unlimited data and start backing up anything and everything. If the data plan is limited, as most of these services are, you'll start eating through your allocation fairly quickly. Thankfully we figured it out before I hit any big overage charges. So before you connect your iPhone or iPad, make sure to turn off iCloud backup and photo stream to avoid exceeding data limits.