I am not suggesting anyone buy any radio, just saying what I have been told.
I suspect people have problems because they do not know what they are doing, or do not know much about radio or computers.
I have had almost every SDR and have never had any problems with any radio not working correctly.
I get a half decent computer ($250.00) and only run the sdr, no other programs at all, and they just work.
I also ground my station and even though the antenna is close to the shack, I do not have problems.
I know very little about computers (software really) but know you will not have good results if you use a windows computer for sdr with updates on, and virus protection running, and use it for Email and shopping, and logging, and digital programs and the kids play games on it, and it sits on top of the amplifier and has 30 foot speaker wires running all over next to your end fed antenna.
I might point out this is the SDR FORUM so not wanting a computer is a bit odd since you NEED a computer (of some sort) to run SDR.
There are only a few real sdr radios where you do not need a PC, others have band scopes and dsp but are not the same as what something like an Anan can do.
The Icom 7300 is a real sdr radio but because it does not use a PC, there are MANY things it can not do.
Since Flex moved a lot of the sdr work into the radio, they are now very limited in what they can do.
I suspect nothing out there other then the Anan is really going to do better then the MFJ thing you have now....