I had the free flap 3 years ago to reconstruct about 1/3 of my tongue, and except for the scar on my wrist, no one notices anything; speech is normal, eating, swallowing normal. (Even the neck dissection scar "just looks like another wrinkle" my 10 year old granddaughter told me last year)
I was at UCLA, was in surgery about 9 hours, had a trach and a nasal tube for the week I was in the hospital; was talking and eating before I left, and both were removed before I left. Took pain med for about two days after, and was able to eat almost normally very soon after. Very unremarkable recovery - skin graft on thigh was slowest to heal, and probably the most uncomfortable.
I had weekly massages for a year after the surgery and still get every other week. I think the attention to the dissection area helped with the lymph swelling and scar tissue; My neck gets tired and is achy sometimes, but not much worse than before surgery. I find a spot once in a while that doesn't have full feeling, but everything is pretty much back to normal.
I know I'm very blessed to have had such an easy recovery. I was surrounded by family and friends and covered in prayer. I'm very thankful that there is even such a thing as tongue reconstruction!
All that said, I wouldn't look forward to having it done again! My kids tell me the first few days were worse than I remember - said I was a little goofy on my pain meds! I started talking as soon as I woke up - just wasn't very easy to understand for a few days.
Good luck with whatever treatment you decide on.