We just did a business with 5 of the 2160s and around 20 of the 1405s 2 weeks ago..The 2160 is great for them...
The 2160 is probably the best deal if you've got a bunch of other extensions, as it's not a huge price bump,a nd offers you a ton of BLF options.. very handy to look at your phone to know if Bob is on his phone or in his office, without having to walk down the hall...
the 2200 sidecar is pricey - - a LOT more than just buying the 2160 has 24 buttons on it
that said, the 2130, 2140 and 2160 ALL have a very screwy issue (which I havenn't yet figured out)---headsets that work PERFECTLY in the 2100 wont' work in them... and in fact, i've yet to find a single headset that WILL work properly in any of them.. Kinda sucks because we've got 5 or 6 different clients with the 2130s and 2160s, and we've not been able to get a good inexpensive headset solution for them.. (by comparison, you can get a $15 headset on Amazon that'll fit the 2100s and works beautifully).
My guess is that the 2130/40/60 use a different amp in the RJ9 headset jack config, and it's pretty pathetic.... If anybody has a solution, let me know!!!
i wouldn't be putting one on the desk of somebody who's just using the phone 2 or 3 times a day - it's total overkill for that.... BUT there are some real advantages for BLFs and ringgroup, intercom/paging, etc - - spending a little time programming that phone will make it way more productive of a tool... but you knew that, of course.....