I started inadvertently transitioning in late 1999/early 2000. Once natural, I would dye my hair, grow it out, cut it, and repeat. In 2007 I relaxed my hair on a whim.

Pros:
FINALLY seeing my length. I went from 2 inch TWA to shoulder length hair. I was like OMG, amazing!

Ease of styling: I could wake up, gather my hair in a a ponytail and go

Variety of styling: I'm not the most eye-hand coordinated person, so with relaxed hair it was easier for me to try new styles. (now as a natural I literally do wng, 50 medium twists/braids, or head wrap ONLY)

Healthier edges: Since I'm not good at styling natural hair, I wear a lot of head wraps, which caused some issues with edges. When I relaxed, my edges grew back in.

Cons:
Dryness: When I became natural I learned better hair care techniques, but still, my hair became dry as hell

Breakage: Aside from edges, my hair began to break off even though I babied my hair

Naturalistas: Got a lot of ish by natural friends. However, I dare them to say the ish they said to me to Maya Angelou who sports a relaxer.

Ultimately, the dryness/damage was just too much. I have baby fine hair that is very fragile. I did not touch up the relaxer, and after a year cut it all off.

I think even if you have excellent hair care techniques, your hair will not be as healthy as your natural hair. However, you may be able to maintain hair health. Ultimately, it's up to you. Do what you like. It's your hair. Worst case scenario, it gets damaged and then you grow it back.