I would be willing to put up with a more-massive phone -- especially a thicker one -- in exchange for longer battery life. Would also like a larger screen, mostly because I'd like more space for the onscreen keyboard.
I entirely understand people -- especially women, with clothes designed to often have smartphone-unfriendly, small, form-fitting pockets -- not wanting a large phone. There is also a market for smaller phones, and "bigger phone" is not the answer for everyone. But I'm fine with it for my own phone.
My #2 irritation is that I miss having a phone connector. I understand why manufacturers did it; it bought them a bit more space. I do like having active noise cancellation, and that requires some way to get power to a phone. But there are a long list of things that I like about having a simple, zero-latency, splittable, mixable, inexpensive, always-works-protocol cable that has been on pretty much every device for over a century. I don't have to worry about charging headphones. The 1/8th inch headphones jack is pretty durable.
My #3 irritation is that the industry -- spanning cell service providers, hardware providers, and software providers -- has the desire and is willing to try to make it harder to use phone data with tethered devices than with a phone device. I have no problem if you have quotas and then throttle when they're exceeded or something. I have no problem with you prioritizing a user who has made the least amount of usage of their quota. I have no problem with you even selling prioritized data. But for God's sake, you have no legitimate reason not to be hardware-agnostic. Don't try to dictate what I'm doing on my end of a data connection. Wired ISPs don't do this. You want multiple devices on the other end of your data service, they're fine with it, even provide hardware to do NATting if required on ISPv4 networks. I appreciate that wireless frequency is a scarcer commodity, but needing to make use of it intelligently should not entail caring which device on the end user's end is consuming it. If PC-tethered users are consuming way more than their share of bandwidth, then just throttle heavy users.