Upgraded to the Venture from Quicksilver last year and I recently converted my account back to Quicksilver. The main reason is although you earn double points for every purchase with the Venture, the annual fee means you need to spend at least 8,000 to break even and start earning reward dollars. Secondly, when you want to redeem the points for something other than travel (or what Capital One recognizes as travel) you only get 50% of the value on your point redemption. Example: I take a trip and want to use reward dollars towards an expensive restaurant; if I have 20,000 points, and I redeem them for the meal, they are only worth $100 instead of $200 if I redeem an airline purchase. So, if you're not smart, you could be paying the $59 fee each year, spending less than $8,000 on the card, and redeeming your points for half of their value -- essentially losing money using the card instead of making money from the bank. If you stricly redeem for airfare purchases or train tickets, and spend a great deal on other purchases, it can be very simple. As for me, I didn't like to make airline purchases using the Venture to make airline purchases because I earn more points using the Amex Premier Rewards Gold. I would rather redeem Chase Ultimate Rewards or Amex Membership rewards points because instead of 1:1 value when using points, I can earn a 2:1 or 3:1 ration when transferring to certain airlines or hotel partners.
In the end, once I had accumulated substantial rewards, I converted the account back to Quicksilver and cashed out the points for 1:1 value. So now I have no annual fee but a guaranteed earning and redemption rate on my points.
In conclusion, the Venture card is good if you want no frills and use the card exactly the way Capital One advertises, for travel,