Greg Cox wrote:
Easier to just write "Kirk beamed down to the planet" than "I beamed down to the planet" and have to make it clear who "I" is in each scene.
If the reader is several chapters in and still has trouble remembering who "I" is, either the reader has a severe attention-deficit problem or the book would be awfully damn boring.
Marion Zimmer Bradly combined first-person and third-person povs in her novels Heritage of Hastur
and Sharra's Exile
; the chapters alternated between the third-person pov of Regis Hastur and the first-person pov of Lew Alton (described as "Lew Alton's narrative"). It was an interesting technique.