It doesn't have to be an either/or thing. I bought a used recumbent two seasons ago and rode it exclusively for about 6 weeks @ 200-300 miles a week including a late season 400k. I like riding my recumbent a lot, but I still prefer my uprights for brevets because it's more fun to ride with other people who are on the same kind of bike. So last season I rode uprights pretty much exclusively until the Fall. I would ride my recumbent a lot more, but the muscles it uses are a lot different and I'm afraid it will make me slower on my uprights if I spend too much time on the recumbent early in the season.