I recently bought a Fluke 189, and it's a great multimeter. My only wish is that it could measure beta/Hfe, but I don't think *any* Fluke DMMs will measure that. I had been using a Fluke 27 for a long time (also a great DMM,
built like a tank), but the lack of capacitance measurement was what drove me to get the 189.
If you want to know how the 170 and 180 series compare, check out
this page. I don't know what the 4 wires resistance measurement is, so I can't help you there...
Fluke makes really great DMMs; they're very pricey, but they'll also last a very long time. My Fluke 27 was actually passed down to me from my Dad when I went to college. If there's a such thing as an heirloom multimeter, Fluke makes them
.
The pictures on that ebay auction look legitimate; my retail-bought 189 came in very similar packaging.