I'm biased, but I would hate to be stuck with a 3.6 kW OBC. Think of it this way...
At 6.6 kW charging rate, you can add 6.6 kWh to the pack after one hour (assuming a steady charging rate and no losses). Reality is more like 6.4 kWh. For a 2014 Leaf, 6.4 kWh is roughly 30% of useable pack charge. Also, assuming 4 miles/kWh, that's roughly 25 miles of added range per hour.
At 3.6 kW charging rate, you can add 3.6 kWh to the pack after one hour (assuming a steady charging rate and no losses). Reality is more like 3.4 kWh. For a 2014 Leaf, 3.4 kWh is roughly 15% of useable pack charge. Also, assuming 4 miles/kWh, that's roughly 12 miles of added range per hour.
Over night charging, assuming a 240V EVSE, isn't really a problem.
However, you'll find that there are times when you are home for a couple of hours and then you need to go out again. Also, it's nice to charge for free when you stop in somewhere for a meal. Having the 6.6 kW OBC means I can add almost 60% useable pack charge in 2 hours - same at public EVSEs.
With a 3.3 kW OBC, it's those adhoc charging scenarios when you'll get frustated with how slow it charges. The 6.6 kW charging is bad enough, I would love to be able to double or triple that rate.
Of course, I have the luxury of a DCQC when I'm going on longer trips and can plan ahead. Unfortunately, in Vancouver (Canada), we don't have many DCQC stations so adhoc charging really only happens if I'm lucky enough to be in the right neighborhood...