I have both and have been Beta testing Limes for just over 2 years now. I know the traditional LimeSDR in its V1.2 Beta and V1.4 production and just acquired my Mini about 3 months ago Beta. Here is my impression:
First off - and this isn’t an RF issue, but the Lime-Mini departs from the usual MyriadRF USB driver and uses an FTDI driver instead. Without that driver installed, the Lime-Mini cannot communicate on USB 3.0 - - so be looking to install that right out of the chute. Here is the driver installation for that here (Win7 - 10) ----> https://wiki.myriadrf.org/LimeSDR-Mini_driver_installation
From an RF perspective, the major difference is the lack of HF receive capability below 10 MHz - there isn’t any. The Lime-Mini can only tune 10 MHz to 3.5 GHz (the traditional LimeSDR can tune decently from 500kHz to 3.8 GHz). I have been running the Lime-Mini from Windows and in the VHF band it has very similar performance to the LimeSDR. Here is a Youtube video that shows that ----> https://www.youtube.com/watch?v=kWpnU46MnXA . On Linux, I ran a UDOO Advanced Card with Ubuntu 17.10 (Artful) with similar results - good receive on VHF -----> https://www.youtube.com/watch?v=m9fIFdxezF0 .
I haven’t had a chance to record a video with transmit yet, but I can assure you that it does transmit well into the VHF band on 2m when I tested it at the house just using radios across the room. Good, clean transmit is what you can expect.
Let me know if you need anything further here - I can certainly help where I can.
73 de Marty, KN0CK