Depending on your love of chocolate, you might want to increase the amount of chocolate chips to a full cup.
I also thought muffins came out rather bland so I made a few alterations. I would recommend substituting the white sugar with packed light brown sugar; increasing the spices to 1 1/4 tsp cinnamon, 3/4 tsp ground ginger, and 1/2 tsp nutmeg (I did not have any pumpkin spice or ground cloves); and increasing the pumpkin puree to 1 cup. These changes produced more flavorful muffins. - 09 Nov 2004 (Review from Allrecipes USA and Canada)
I made these and they were a big hit!! The people at the party I took them to claimed I had put an addictive substance in them :-) I used packed dark brown sugar instead of white, I used 1 cup of pumpkin instead of 3/4 cup, and I doubled the cinnamon and nutmeg. I also made them into mini muffins, so I used mini chocolate chips. cooking the minis for 15 minutes worked well. - 13 Oct 2007 (Review from Allrecipes USA and Canada)
This was a great recipe although me and some of my taste testers thought there was too much chocolate chip. I think I will try mini chocolate chips or chocolate shavings next time. Also, I "wetted" the chips then put them in with the flour mixture before mixing in with the wet. This coated them and helped to prevent the chocolate from falling to the bottom. These muffings are also wonderful with homemade cream cheese frosting! oops one more thing, I found 400 was too high and burned the outside. 375 for 20 minutes was perfect. - 18 Sep 2006 (Review from Allrecipes USA and Canada)