Nice multimeter, but I still don't understand why they need the laser trimmed resistors. I understand this for older multimeters, with less processing power, but should be no problem to use just 1%, low tempco resistors and then calibrate it in software. The Freescale microcontrollers on the board have even a double precision floating point unit, and they run at 800 MIPS, so even at 1 MHz samplerate should be no problem to do one more multiplication per sample.
I've seen 2% resistors even those were laser trimmed. Things like the 10 Mohm input impedance doesnt tolerate too much difference.
The general feel of the meter it is like it was snapped together. I really dont like the construction, all those million cables zapping everywhere and boards in every direction... That coax transformer especially. If you need to design a low noise power supply, design it properly. There are options like PCB planar transformers ZCS, and countless methods to generate low noise power. Probably half the guard rings and slots are not necessary. When I say those pins of that dual Jfet in the air
This dual gigahertz CPU is also... I mean cmon, I know that processing power is cheap but do you really need that?
Dave the you cannot appreciate the 3458A until you used it. The first few days I used it I was yaw dropping and smiling, saying that "I can measure stuff that I didnt even thought I can measure". Like potential increase on a solid ground plane after turning on a LED. Probably it even has faster display update than this Keithley.
Probably the end result is still good though. I mean the specs are very good, and it does the job.