I use an Ipod, it has worked great, and easily doubled my find rate.
Here's my process. Normally I use Pocket Queries to get the latest list of caches that I'm interested in. The Query runs a couple of times a week and is emailed to me. I take the query file and load it into GSAK, then upload the data using a macro. I take the same query file and upload it to my GPS using the Garmin software.
Sounds more difficult than it is.