It really is personal preference. Neither one is intrinsically better than the other.

First of all, IMHO, no pool is a good "investment". Adding a pool to most houses is usually neutral when it comes to resale value, although may not be true in certain regions/markets. What you are really investing in is your own enjoyment.

Vinyl is much less expensive in my area, and the pool will be finished much faster. This is why it is much more popular choice among pool owners that I know. I chose gunite for several reasons, including:

1. Dogs. I have two golden retrievers that love the water, and I did not want to worry about liner tears.
2. Appearance. Don't get me wrong, there are very good looking vinyl pools out there, I just prefer the way a gunite and tile pool looks and "feels".
3. Custom design. Gunite allows for just about any design you want. I must admit, however, there are a lot of vinyl shapes and designs to choose from.

My advice would be to look at and swim in both types of pools, and then decide what you prefer at a given price level. Both can provide many years of enjoyment.

EricF