I really love my K3. Normally I build a lot of my own equipment and also tend to convert older stuff for operating convinience. I've never traded up very much to the latest and greatest but recognize that there comes a time when the Caddilac of yesteryear needs replacing.
So the ol' TR-7 which I've used from everything from an antenna pruner (low pwr SWR method) to a 10 to 20 watt carrier generator for a much larger transmitter was starting to show its age, not to mention the desire of today's ham for exact frequencies with subsequent channelization. Everyone knows that putting a heat generating digital read-out board in what was originally designed for analog readout causes warm up wandering. One digit past the decimal, charming as it was in '81, didn't help either. So, what rig to get?
Amazing reviews of the K3 when it came out along with finding design information from w4zcb, the British connection, and early development of the digital IF section helped comvince me. Sherwood's stats more than helped too. The option of using only the 10 or so watt PA as a stand alone, reasonably clean carrier or even fully modulated SSB or AM (2.5 W carrier) looked pretty nice too. Well I did get the 100 watt PA and internal tuner, um hm.
A lot of us want to start our K3's in minimal garb, but as the catalog and fellow hams' experience grab us, nothing but a full blown, tricked out K3 will be enough when the final "buy" box is clicked. I resisted that urge... Um, yeah, well everything but the second receiver and VHF boxes. Building the kit was a blast. Never have I seen such a neat and solid case, almost monocoque after the 2D connectors made what were just flat pieces of metal into a tight tolerance monolithic shell. Amazing.
The receiver is pretty darn nice, even 10 years or so after the original design. I've coupled it with a QS1R via QsCat, etc. and can compare both, use the transmit function and T/R relay of the K3. Just having only two "main" transceivers in decades hasn't arrested my other experimental interest. A few things have been toasted along the way too. ...don't ask
Menus took some getting used too. All the possibilities and multiple functions, audio tayloring, memories, macros, etc I may use eventually. Some functions are not intuitive, but some functions are very usable, and hardly thought of in previous eras. Switching from from front panel electric mike (biased) to rear panel dynamic, (non - biased) has been pretty neat.
Well I could go on and on, ... Price point compared to the "K3 killer" TS-590 has just increased the sales for both. Both are fine, one more ultimately expandable, one with microwave case, one with monolithic case, etc. Your money on a k3 goes into a fine innovative product, eminently copyable it seems.