United and Southwest typically have high/crappy redemption rates for their miles programs, the better value for Chase airline transfers are usually with the international airlines like Singapore Airlines and KLM/Air France. Sometimes (alot of times) its better to just pay cash for domestic flights if you can find better deals with cash.
The absolute best value right now is transferring Chase points to Hyatt hotels. You can get a category 5 hotel, for 23k points per night, which is ridiculously low. A similar tier hotel with Hilton would be way higher. Although, Hyatt announced theyre going to raise their rates in May, so book now while you can.
The key with Chase points is you want to get at least 2 cents for every point. For example, 10,000 points is worth $100 in cash value. If you can find a cash flight for $100 or less, and that same flight is 10k points, then just book in cash. Its probably not worth using Chase points to book on the Chase portal unless you can find a really good deal, which is unlikely.