With phones it's all a little janky.
First of all you have to know, whether you are interested in Gear VR, it is technically "with phone" as you mentioned and the highest end on the "cheap" VR side, provided you have the phone. No questions there, GearVR beats all Cardboard variants.
As for Cardboard, don't use Google's original design. It's horrible. If you are interested in the cardboard format, made out of cardboard :D , then look for the Knox Lab V2. It is the best under the cardboard designs and has a real touch button. (Original google had a magnet button instead)
One thing was never mentioned with Cardboard vr out of cardboard: Sweat stains. It's a real problem and very unpleasent for clients to give, if there is a forehead shaped sweat stain.
The next one I have experience with is Homido Mini. A very very very small sized pair of VR glasses. It works surprisingly good, but due to it's ultra compact size, it has no Button.
As you will see around VR tours of other users on the Forum, this is ususally not a problem, as tour designers like krpano just use "look timers" as ways to go to the next scene. It's also cheap.
With Cardboard solutions like Homido mini and Knoxlab V2, you will never get more than 5mins of "comfortable" usage out of. It is just not that immersive or comfortable in the first place.
The more important part
is your phone. I have a 1080p 5.5" Screen. All of these devices are made for screens of 5" to 5.5", and best if you get a 1440p screen, as the resolution bump is very noticable. (like the lg g3 on the cheap side)
You can counteract this, as the good VR apps can adjust for different screen sizes, but the glasses cannot, so it works only to an extent.
These are the two I have experience with and can go into in more detail, as for other solutions, hope you will find some info there.
One more thing.
DO NOT TRUST default settings in ANY VR app with cardboard.
Use this site to decode the QR Code (site only seems to work with long URL, when you read out the QR code yourself) and get the Distortion coefficients and real fov. You can type these values into VR apps, like krpano and it makes stuff SO MUCH better. Just don't trust shotty presets.
