- Capability. Both screens are capable of accessing all the Portsdown's features, except that the 7 inch screen disables the Raspberry Pi video output, so this is not available with the 7 inch screen.
- Form Factor. The 7 inch screen means that your Portsdown needs to be larger (at least 3U if rack-mounted). The 3.5 inch screen allows for smaller builds.
- Ease of Mounting. The 3.5 inch screen is difficult to panel mount. The 7 inch screen has screw fixings and there are some very nice commercial enclosures available for it.
- Responsiveness. The 7 inch screen appears to be more responsive, as it is updated at >20 fps, whereas the 3.5 inch screen is only updated at about 3 fps.
- Reliability. A number of constructors have had the 3.5 inch screen fail, and had support problems from Chinese vendors. The 7 inch screen seems more reliable and has the after-sales support that you would expect from a major UK vendor.
- FreqShow. Freqshow works with both screens, but it uses touchpad and cursor mode with the 7 inch screen, so is not so intuitive.
- Brightness. The 7 inch screen is brighter than the 3.5 inch screen - some have even complained that it is too bright indoors.
- Wow Factor. The 7 inch screen looks great!
- Support. I am aiming to continue to support both screens (as I use both in my shack).
- Testing. I will only test new enhancements with the 7 inch screen using the Stretch build. They should work with the older Jessie build, but I am not able to test them.
- Cost. The 7 inch screen is about £60 whereas the Waveshare 3.5 inch screen can be purchased for under £20.
Dave