iPhone 6 vibrate intensity is very very weak compared to previous generation iPhones.

Here is my verbatim complaint to apple:

The vibration patterns for the phone are so weak that I can't feel a text coming in while the phone is in my shirt breast pocket. I was recently at a religious function and when they saw me with the phone I got the stink eye and put it in my pocket. Consequently i did not know that my sister was having a medical emergency. She was alright by the end but she was plenty ****** and me. Now I am plenty ****** at you.

Added now and God was ****** at Apple too which is why their stock is slumping.

I Just upgraded to the iPhone6s from the iPhone 6. I was experiencing this same issue of weak vibration. I thought the phone was defective at first as I did not have this problem with the iPhone 6.

However, once I changed the txt alert ringer to one of the choices under "classic" the vibration returned to the same pattern and strength that I was accustomed to in older models of the phone. I hope this works for you!

finally I found a way to change at least the pattern..

https://snapguide.com/guides/change-the-vibration-pattern-on-your-iphone/

Folow the steps on this site to set the ring tone, but at the of that selected ringtone is an option for vibratation -> Default, so far, I like symphony, it has a randomness to it that helps you feel this week vibrate that is the default.

I miss calls and text often. I was happier with my old iphone4

Problem with shifting the ring/silent switch to Ring is that it then gives Sound to all of my Apps. Throughout the day I do not want them to use Sound (particularly if I'm on a phone call and also looking something up). So Silent mode is perfect, but with my iPhone 6 I can no longer hear it, even just sitting face up on the table next to my laptop, I can't hear it ring. The previous versions all the way back to the original iPhone had a vibrate that was audible enough to notice the call coming in.

They need to fix this and make the vibrate more pronounced. I keep missing calls

To me the point is for the rest of the room not to hear it but for me to hear it only. That's the whole point of vibrate. If you didn't want to hear it, you would use the silence button. If I'm at the library, I don't want to miss a text or call by using silent, but can't use loud bc it would disturb everyone, so vibrate is a wonderful alternative to both options. I hate my iPhone 6 Plus vibrate it's so soft I may as well not get this feature at all!

I have the same issue, and I am sure everyone that owns an iphone 6 has the same issue. I found that turning on LED alerts greatly helps at night or when the phone is on my desk, Just an idea.

I Found the vibration too loud on my 6, so I ended up disabling it. Just keep your ringer on. You won't miss anything this way.