Graco Height . . . Toby?

My daughter is approaching the 26" limit to her Graco Snugride. My question is this, if her head is nowhere near the top of the seat (she's got really long legs) then do we really need to move her up to to a convertible? We are planning on buying a RA or Advantage, but I'm not ready to give up the convenience of carrying her around in an infant seat. Is there any problem with her feet touching the seat back? Thanks for the help.
Jen