Last year I replaced the vinyl top on my TR6 with a Sunfast fabric top. I really believe it looks better than the one I replaced.
I also helped a friend put a vinyl top on his 74 Spit. The vinyl is a little easier to work with. If memory serves me well, the vinyl top may have had pre-installed snaps, whil the cloth top did not. I think it is advantageous to not have pre-installed snaps, as it is possible that they won't line up exactly with the snaps on your car.
To put a top on takes a little work, but if you do it slowly and measure everything 10 times before making a cut or installing a fastener you will be fine. The toughest part is up front, getting a smooth mount and planning the right amount of tension. Too much and you need a couple of people just to raise the new top, and too little you won't get a good smooth fit. Be patient.
Two people working together make it easier, and tend to keep spirits up, though one person can do the job.
I think there is some good guidance elsewhere in VTR articles (
http://www.vtr.org/maintain-index.shtml) that will give you some good guidance and perspective.
Don Larimer
Maintenance Issues
