Tried Nielsen's the other night after going to Sheridan's up on Eastern, but Sheridan's is more of a walk-up stand, and did not offer indoor seating on a cold and windy night. Nielsen's did have indoor seating (will try Sheridan's on a warmer night when in the mood for a treat.)
Nielsen's is located between Grimaldi's and Cafe Rio, a good strategic location as we say many people coming over from these restaurants for dessert (with pizza boxes to go in tow).
Service was friendly, and frozen custard was very good - smooth and creamy - options for toppings or mix-in's for 'concretes' were good and varied.
Overall, good frozen custard, pretty rich/filling (spouse and I shared one item - it was more than enough for both of us) - premium price for premium product (although at around $4-$6 per person if all get their own serving, a relatively nominal cost in the schedule of things.)