Depends much on the bandwidth.
Wifi can be faster than UMTS or HSDPA, if the connection compares to LAN bandwidth and indeed is inohouse you can use the ipads comparable to any normal client pc of the lan via paralells.
If the wifi connection is comparable fast, but the ipad is in the private LAN of users, not the company lan, the limiting bandwidth would be the internet connection between private wifi and company lan.
A real installation on the ipad with parallels can offer a better experience in the situations the bandwidth is low. But you would then also need to take care of data transportation to and from the ipads.
If the ipads need acccess to your central server data during the use of the application you are much better off with a remoting solution. Sending screen graphics and mouse moves and keyboard usage back and forth is possible with a low bandwidth. It will get less repsonsive, and have a lag time, the lower the bandwidth of the connection is, but it would even be worse with data access through a low bandwidth.
Only if you can both install application and data locally on the ipad it would profit from not remoting in smooth usage like on any client. For that you at least need to add the capability to check in and out data from the central database to a local database on the ipad.
It's much easier to first try a remoting solution and then decide to go for parallels or something similar and add a data exchange between ipad and central database if the remoting turns out to be too slow.
Bye, Olaf.