I am currently  finishing the work on agreservations 6.4 there will be a code freeze in march for the 6.x line of themodule. After that i will only work on 7.1. The good news is, the 6.4 version is becomming more and more stable,by march i will have a release candidate of agreservations 6.4.  Here is what is possible with the software:

• define categories like room, house, car, boat....
• you get automatically blocks with search forms for each category which you can activate in the blocks section of your site.
• These blocks provide the online booking functionality where anonymous users can check for free resources and book AND pay.
• The Receptionist or Admin, gets an email for each booking.
• Also the Receptionist or Admin can check in the bookingcalendar which resources are free on which day
• The Receptionist can make Walk-in guest bookings AND creating orders, from the ubercart create order form OR from the bookingcalendar (since today the later is possible :-))
• There are rates you can define like, "doubleroom highseason", "doubleroom lowseason" and you can assign time_frames to these rates. (This will be explained in detail)

If you set it up like on the hoteldemo.mightech.de site you have a pretty decent All in One Solution for a small hotel.Of course there are a few more modules installed on the demo site to achieve this. I am planninga Distribution including the SAME functionality like on the demo site. This distribution will be available for download for a fee or by paying for a subscription. It is indeed possible to achieve the same functionality by installing and configuring manuallyall the neccessary modules. The benefit of buying a Distribution download is the saving of time....and time is money,plus, you get support depending on which package is choosen and you have access to updates of some moduleswhich i maybe will not publish on drupal.org. (Like an availability calendar showing not units, but unittypes which  links to a comfortable configurable booking formular for online visitors)  If there is some interest and i will be able to earn some money withthis, i can reinvest it to further improve the software. From my point of view this can become the most flexible PMS system because it is using the most flexible CMS there is.