I asked this question to both the sales people and the shop guys before I bought my G6 bronco. Everyone said "don't, just get the hard top. It's easy to remove and not worth the effort to convert." I haven't done the hard to soft conversion, but since buying my hard top and taking it off I can say it's not hard to do and I'd go hard top if you want to go top-less. HOWEVER - The hard top back piece is big & heavy just because it's big and awkward, and awkward to balance and move -(oh wait, I said awkward already.) It's really a question of how often will you take the whole top off? Will you always want all the top off, or just some, and how much storage space & security do you have once you take them off provided you have the space to put them in your garage, or VRBO, or Air BNB, or camp site?
I wanted soft top and went hard. The pieces are really light and easy to remove and I don't have to retract the whole thing. Just the front seats or all the seats, or the whole thing front to back. I'll deal with security of those bits if and when ever I have to. Cable locks are cheap but I'm not sure how that would work or if it would work yet. I'll deal with that when and if it ever comes up.
I didn't get the opportunity to play with the soft top enough to see if I had those same three options at any speed. In the end the hard top appealed to me, especially once I fell in love with the higher options and decided on a 4 door Raptor....
But, your results may vary...