Welcome to FlyerTalk!
I have had a mileage based card for years. The miles earned on this card have enabled my family of three to visit places like Alaska (3 times), Australia, New Zealand, Hawaii, Europe (3 times), Canada (3 times) and Chile. The mileage earned from the card supplements that earned from flying. Today, you can charge just about everything on your card. We have 2 cards: an AA Mastercard and a Starwood AMEX card. The Starwood card is great because you can convert points into almost any airline program and you receive a 5000 mile bonus for each 20000 converted. The Mastercard is necessary since there are a few places that do not accept AMEX.
Over the years, it has gotten more difficult to get award tickets, more so for business and first class than economy. It is important to book your travel as far out as posible. You can do this up to 335 days in advance.
If you like to travel, you will not regret getting a mileage earning card.