For most peoples' purposes, the XD9 works just fine. Street price is usually about 100 bucks less than a Glock and it's "basically the same thing" to a lot of folks, so I've sold a ton of them. I don't recall any needing to be sent back to Springfield (except for the XDs recall) and in my experience they're reliable as anything else. Though I did have a lady bring one in that had not only never been cleaned, but apparently dropped in a river at some point as well (the lady didn't know how to field strip it and was afraid to try), needless to say it was 100% useless until I hosed it down for her. I can't comment on long term durability having never owned one, though I'd bet most that buy them probably don't shoot more than a couple hundred rounds a year so I don't think it's an issue that comes up a lot.
The XDm OTOH seems to be fairly popular in competitions but it's ridiculously overpriced.