It's Only A Cover-Up. Since vinyl siding is typically installed over your old problematic existing siding your current problems may continue to get worse. Additionally, since vinyl is not tightly nailed to the home, it invites insects and moisture to build behind panels, potentially penetrating the structure of the home.
It's Flammable. Vinyl siding will melt or warp when exposed to a significant source of heat or flame. Some cases have even been reported that vinyl siding has melted and warped due to the heat from the reflection of the sun from a nearby neighbor's window.
It Fades. If you've been told that vinyl siding lasts a "Life-Time", think again. Over time all colors are going to fade from the sun. So with vinyl what are my options:
Install a replacement piece. Good luck finding a matching color.
Pay to have the entire wall, or house resided with vinyl again.
You can attempt to paint it, but because it was designed to expand and contract with climate changes, painted vinyl panels tend to crack and peel over time.
The Warranty. What does "Life-Time" really mean? Be sure to closely review the warranty's fine print to see what is truly covered and for how long. Review closely a vinyl manufacturer's definition of "Normal Weathering." Ask your vinyl sales rep how much is (4) Hunter Units. In addition most of those warranties have confusing pro-ratings that almost always favor the manufacturer.
Curb Appeal. Although vinyl siding attempts to imitate the look of wood siding, aesthetically it falls short. Many would argue that its overlapping seams and faux wood grain are very unnatural, leaving the home looking like plastic and lacking curb appeal.