Is the crown too big? (photo)

Thanks for your question. Based on your photo and question, there are a couple things I'd like to mention. It sounds like the bite on the new crown is incorrect. A crown should feel balanced with the rest of the teeth and should not feel like its hitting first when you bite. This can easily be adjusted at a followup. In regards to the aesthetics, a single central incisor crown can be very challenging. I do believe that the aesthetics of your crown can be improved. The crown can be recontoured and sculpted by your dentist to help give the illusion that the porcelain is less wide. An alternative would be to have a new crown fabricated as well as a veneer on the adjacent central to give more flexibility in aesthetic improvements in both shape and color of the front two teeth. 

Both front teeth are wide and short and out of proportion.  The shortness makes them look very wide.  Ideally I would like to see crown lengthening and longer teeth to make them look like teeth not chicklets.

The one tooth could be recontoured for a better look  and contacts and/or occlusion could be adjusted.

Was this done in a single visit?  As in CAD/CAM Cerec crown?  It can be difficult to create a perfectly symmetrical crown to match the adjacent tooth, but some "sanding" between the teeth can alleviate some pressure.  Too much and a gap will form, so "less is more."  The bite can be adjusted a "little" but too much can thin the crown, leading to fracture.  Crowns are often a little bulkier to be thick enough to withstand fracture, so you don't want too much reduced.

The width of a crown is dictated by the location of the adjacent teeth.  A "perfect" scenario would require multiple teeth crowned/veneered at the same time (8-10 ideal, 2 centrals minimum), allowing the dental lab to create perfectly proportioned and symmetrical restorations.  Less than that means living with compromises, which is often acceptable.

Doing one central incisor tooth by itself is one of the most challenging things a cosmetic dentist can do. 

The first thing I notice is that the new crown is wider than the other central incisor.  Usually dentists strive for two things, one to make the two front teeth symmetrical, and the other is not to have any spaces.  However, in your case if he had made it the exact same size as the other tooth, you would have spaces.  As far as thickness, your dentist may be able to reshape the crown to make it look smaller.

If you feel pressure, your bite probably needs adjustment, especially on the back side of the crown.

However, if you were my patient and had high expectations, I would have recommended doing a veneer on the adjacent tooth, thus making both teeth the same size, length and thickness and out of the same material (as opposed to one in porcelain and the other tooth with natural enamel and a composite filling on the corner).  This would give you the best esthetic result.  

If you feel like you are hitting the back of the tooth too heavy and it feels like it is moving, the bite should definitely be adjusted.  If it feels bulky on the back at the gumline as you describe, that could most likely be reduced somewhat without damaging the restoration.  It looks like the Dr. did an excellent job with matching the color as that is very difficult to do with one central incisor restoration.  Possibly the side of the crown could be reshaped to make the restoration look a little more narrow and match your natural tooth better.