I hung vinyl for about 12yrs. It's not a bad siding, but there is better. I wouldn't hesitate to use it. The insulation would be a bigger concern for me. Not only does it slightly help with R-factor, but it also gives a smoother surface for the vinyl. If you have a lap siding now, it will look pretty bad if you don't use something to help the siding lie flat. More on reddit.com

My house is 105 years old with wood siding. I have about 8-9 boards that need to be replaced. That said, my whole house is all real wood, no plywood, no chip board, no particle board anywhere, no plastic. Metal roof. My parents first house was built in the 60's with part brick & part wood siding. When they sold in '99, it still had all the same wood siding. If it's real wood, it's unlikely that all of it is actually that bad. I disagree with any service person who takes the "just replace everything" approach. They are often doing what is easiest for them**, not what is best for your house. Easier for them has a bigger profit margin.** Definitely get more quotes with the same "the inspector pointed out these spots" data you gave the first guy. You may very well have a lot of currently hidden bad siding, but you could also have 8 or 9 bad boards. At 30 years old, it could have been built with crappy materials that have reached the end of their life. More on reddit.com