Unless you get an incredible price on it, I'd get something newer. There's a hard drive in there that's going to fail sooner or later--possibly sooner, given its age.
I also had the IHP-120, so if they're comparable...well, it was OK, though I never really warmed to the iRiver interface or even Rockbox. It always felt awkward. The IHP-120 is very finicky about its charger, and can be fried with the wrong charger, so you might want to check that with the H340.
It has an integrated rechargeable battery, which also has a finite life span, though I see you can get replacements on eBay or use an external AA pack.
The drive makes noise spinning up, so you won't be using its internal mic for voice recording, if you care about that.
People loved the iRivers because they were so tweakable--wow, you could take out the hard drive and replace it! (for a considerable price)--but that was back in the day. Units now have better preamps, flash drives and expansion slots, and they run on AA batteries and that's all an improvement over the old school. The H120 did have digital in, but I don't think the H340 does.
Basically the state of the art has improved. I see some people are paying over $250 for complete kits on Ebay, and I don't see why anyone would do that when you can get a smaller, lighter, better recorder for the same price.