Exactly my experience. After one year, half the Rain-X blade is hanging off the wiper.I like the Rain-X Latitudes and I get them cheap($5-$6 each), however my issue with them is that the wiping edge tears in about a year or so. It usually starts tearing on the top and/or bottom and I can often snip it to stop it from spreading, which helps them last longer.
If they cost me $5-6 this might be acceptable, but not at the $11-$12 I have to pay for them.
Michelin silicone has been working well for me. If you can get any blade under $5 or less, then changing them out more often is OK, as long as they work well for at least 6 months.