Pills have worked very well for me. I take one pill buccally three times per day with at least 6 hours between each dose. This way of taking my pill was discussed thoroughly with my doctor and my provider's on-staff pharmacist, who gave me the okay. Placement is between cheek & upper gum, as far up as possible. If I don't have to talk or smile a lot the pill stays in place and dissolves slowly for at least an hour, often up to 3 hours. I look at it as having all the benefits of taking it sublingually, but with a much longer contact with mucous membranes in the mouth.
Lab results have shown a really high spike if the blood draw happens one to two hours after placing the pill. At around five hours my estrogen level is typically in the 200s. If only there were really good peer-reviewed studies and data on the efficacy of the various ways of taking estrogen for transition!