We use travel studio as our booking engine, we love that it's easy to set up multiple sites with different languages/ currencies etc so you can have one site which handles all your needs.The price of their product compared to other solutions seems high at first glance but actually they are very competitive when comparing like-for-like services offered by similar products or other providers from this industry area.
The support team has been fantastic - always quick to respond if there an issue. I dislike how time zones make communication difficult between colleagues who aren't near eachother! Also some features seem outdated such as "booking" pages - these could be updated without having to upgrade completely. It would also help us out tremendously to integrate flight tracker into our website rather than just being able to link directly through to them via email or phone call.