Everyone I know who uses a Quad Lack says they should have started with the Quad Lock.

But they're pricey.

If your budget is limited check out the Delta phone caddy mounts. I've used a Delta for my iPhone 4s for several months. Works great. Cost only a few bucks because Amazon was blowing out the Delta mounts for discontinued phones. It's not as slim and elegant as the Quad Locks, but it holds securely and seems to isolate the phone from vibration. By design it offers a lot of protection -- the entire phone, except for the display, is encased in protective plastic. If the phone frame ever popped loose from the handlebar attachment it would still be protected from most impacts. But for that to happen the bolt would need to strip or the handlebar mount would need to break. Neither is likely to occur.

The Delta mounts can be attached to the caps on threadless stems, or clamped to the handlebar on older quill stem bars like my older bikes.

They are limited in orientation. It's pretty much the handlebar or threadless stem cap only, with the phone mounted in vertical/portrait mode. It *could* be mounted to some top tubes, but only in horizontal/portrait mode and might interfere with knee motion on some bikes.

I use the Delta mount only on my road bike. On my hybrids I use little padded pouches Velcro strapped across the handlebars. Those hold my phone, glasses, etc. I don't look at my phone cycling apps while riding so I don't really need the phone mounted visibly on the bar. It's just more streamlined on the road bike. If I need to access a map or other app I just pull over and stop anyway.