I recently got wind of Agilent planning to discontinue their 34401A series of DMMs, having the 34461A as a replacement. The 34401A is a very popular DMM, being one of the de facto instruments in DC measurements. I have come to favor its brother, the 34411 [counterpart: 34465] which has more features that I occasionally need, like capacitance. For instance, when I have 2 SMT ceramic caps that look exactly alike, but have different values. The 34411 comes in handy. [I could use a "smart tweezer" too but I feel more confident with the 34411]

What does the 34461 have to offer over the 34401? One is Agilent's "TrueVolt" technology" which claims to have the following benefits:
  • Agilent Truevolt DMMs have less than 30 percent of the amount of injected current attributed to the meter compared with other DMMs. 
  • In real measurement situations, input currents create measurement errors, adding voltages to DMM results. Truevolt DMMs take care of input bias current. Other vendors' DMMs offer 20 percent to infinitely poorer performance (some are too noisy to get any measured results).
  • In the 6½ digit class of meters, only Agilent uses digital direct sampling techniques to make AC rms measurements. This results in a true rms calculation and avoids the slow response of analog rms converters used in all other vendor's 6½ digit DMMs, allowing for crest factors up to 10 without additional error terms.
Support for the 34401A series will continue for 5 years after its discontinuation.

See the following videos, links and references for more on the migration:





Migrate from the 34401A to the New 34461A Truevolt Digital Multimeter (DMM) <AGILENT>
http://www.keysight.com/main/editorial.jspx?cc=PH&lc=eng&ckey=2330612&nid=-11144.0.00&id=2330612