Hi jazzjester-
I've owned a ICF-2010 since March 1988. I blew the front-end FETs around 1989. Sent it to Sony, they fixed it, and threw in some extra replacements (which I've lost since then). I can't remember if they added the protection diodes. Since getting it back, have never blown the FETs as I only use the whip or an antenna connected to the whip. The thing works just as well today as the day I got it. I will never, ever give it up.
In later models of the unit, they put some protection diodes in there to the ext antenna jack, but don't know when nor how to identify a unit with them in it. Be paranoid and hook an antenna to the whip and you'll be fine (as the whip does have the protection diodes).
As far as overload... that surprised me. I'm currently in a major metropolitan area with an 5kW AM pest about 5-10 miles away. The 2010 handles that one gracefully. I've never put 120' wire on the radio. At most, I'll put a 25' wire onto the whip. While the extra 25' wire brings up the signal, it also brings up the noise. Its a wash on whether its worth it.
Got a pile of other radios, but as far as portables go, it remains my favorite. And nearly 25 1/2 years later, its still going strong. Tonight, recorded Undercover Radio on 6925 kHz USB with a relay of a show from KIPM on the 2010. The only way I'll be separated from my 2010 is by death, and I'm looking for a way to take it with me.
I'd say keep that one and get a second desktop radio. The 2010 is still a portable with its inherent limitations, but still top notch.
Out of curiosity, how big is your lot? Got 500'+ in any direction? If so, take a look at a Beverage on the ground (BOG) antenna. My lot isn't big enough, but a friend has a 3 acre lot and he's got nearly 500' north to south, so some day we're going to lay out an antenna and see how things work. A while back, put out a 2200' BOG on a country road. LOTS of signals on AM (with my 2010) and took forever to roll that wire back up.