At first, I thought 60 would be adequate, but once we started making a lot of short roadtrips here in the Seattle region, I quickly learned that the SCs are only just good enough to reach most destinations with zero charge, and no spare to actually DO anything (or make it back) unless some form of destination charging is available. Sadly, from Vancouver to Olympic National Park to the Cascades and central WA, even the supply of (very slow) destination charging is very poor and (worse) unpredictable until you get there. I've learned the value of 120 V charging when you have the luxury to hook up overnight, but after the upgrade to 75, it is still very, very tight. Chademo or any fast non-SC charging is non-existent in this region.
Even if I take into account the planned SCs (with no construction evidence in sight), it won't help much, so this will be the case for at least 1-2 more years min.
If you live in the SF or LA area, go for 60, but elsewhere, I wouldn't.
I would definitely pop for the 100D today. It might drive us to a M3/310 model.
BTW, given the terrain around Seattle, a 75 @ 100% can be counted on to have a practical range of about 180 miles with any kind of reserve. I wouldn't count on my original 60 to make more than 120-150 max.
For commuting and day-to-day, 60 is plenty.