There's a lot of design issues that are more of nussiance than anything else. Like screen color and font. In the sunlight it's extremely hard to see the screen well. Looks very washed out. Also the antenna connector. It has a special connector that isn't uncommon per se, just not the average you usually see. Another thing is CPU speed. Granted I'm in no rush to go through prompts and menu options when using it, but for people who like lightning fast. It is not. However when you buy it and do the firmware updates it runs significantly faster, but it's not like a 700 dollar MotoTRBO fast CPU.
Another thing like mentioned above is encryption standards. It has 128 bit encryption ( with latest firmware updates) but it's not the same 128 bit encryption Harris uses or Motorola. Every manufacturer has their own ideas on the exact encryption they use. So hence can inhibit interoprability in that aspect, but that's not s Tytera prone issue it's a issue across DMR radios in general. The 128 bit key Tytera uses is quite secure and the garbled voice output on the Enhanced Encryption standard for Tytera is similar to MotoTRBOs. Basic encryption is well basic in the sense you can't understand the voice behind the transmission, but can tell when someone starts and stops talking between sentences. Much like voice inversion scrambling on analog radios. The enchanced encryption is garbled fully and much more secure overall. Sounds more like DES encryption on ProVoice or P25.