Surround speakers ear level

I've read consistently that tweaters should be aligned with the ear. Yet I've seen surrounds placed on mounts towards the ceiling, and in the ceiling, firing down towards the listening position. Are upwards mounted surrounds suffering quality?

Due to limited space in my living room I'm trying to decide on the best position for the IL10's I am going to acquire soon (I don't know when, but It'll be soon). Space-wise it would be nice to mount them towards the ceiling, but I don't want to inhibit performance. Any clarification would be appreciated.

Does anyone know of good mounts for Infinity IL10's?
I'm one of the group of listeners who think that surround speakers are best mounted closer to the ceiling, rather than at ear height. By mounting the speaker closer to the ceiling (assuming we are not talking about large, floor-standing speakers), the bass response is enhanced (like putting speakers closer to room boundaries to increase bass). Further, being closer to the ceiling is more consistent with providing the "surround" dispersion you want in a home theater setup.

I have a pair of M&K SS-150 tripole surrounds, and they are mounted about one foot below the ceiling, but aimed downward toward the listening area. I arrived at this speaker positioning after a number of other placements, and think that it provides optimal surround.

If mounting the speaker directly against the wall does not provide good surround dispersion, you may want to try using wall brackets that allow the speaker to be angled downward.
I mounted my surrounds up high, on my last home theater set-up. Keep in mind that your rear surround speakers are actually for "fill" to flesh out the sound as most sonic information will be coming out of your front 3 speakers. More critical is setting up your channel levels so that they are as equally balanced as possible. Happy Tunes!