Just as a counterpoint to BrowserUK's comments--I use DBD::ODBC nearly exclusively.

My workload is basically: use the bulk loader to get the data into the database, and use vanilla SQL to operate on the data. For this usage, ODBC has been just fine for me. One thing I commonly hear is that "ODBC is slow". It might be, but I haven't seen any speed difficulties. Of course, I don't execute a bazillion tiny queries--I tend to tell the database to do large operations so that the communications overhead is pretty darned small. So I think I'd advise: "If you're already using ODBC for other databases, go ahead and use ODBC. If you find a speed or feature deficiency, you can always go to DBD::Oracle." In fact, that's what I decided long ago. I've just never been pushed onwards.

Having said that, you'll still need the oracle client software on your machine to use the ODBC interface, so installing DBD::ODBC probably won't save you any time or effort on the installation phase. So if you don't have DBD::ODBC on your machine, and you don't anticipate doing so, you might just try DBD::Oracle first.