I like the feeling of the shave in using a straight...plus I like the fact that it is kind of old-timey. However, if I'm running late, I will use a DE.
I've never used a DE, so I can't compare the shaves. But, I enjoy the complete self-sufficiency of using a straight. Once you have the strop, whetstones and razors, that's it. It's a nice feeling knowing that the edge you put on the blade gave you a great shave. Can't get that (I imagine) from a DE. James.
I switched to a str8 3-4 years ago strictly to save money (ie, cost of cartridges, etc.). At that time I didn't even consider a DE -- I wanted the cost of supplies to go to near-zero!. Initially that proved to be a penny-wise pound-foolish decision -- I bought razors, hones, strops, etc. (eBay became my best friend for a few months). By today's eBay prices, I didn't spend a lot -- but it was certainly more than what I had been spending on cartridges. Then I went through a period where friends and relatives donated razors their fathers and grandfathers used, so the acquisition expenses leveled out. Granted, some of the razors needed restoration work, and that spawned an enjoyable hobby for me. During this journey I picked up a DE which I use when I fly w/carry-on only (ie, I can't take the str8). Both give me a good shave (I'm not fanatical about BBS) but my face likes the str8s better than the DE. It's been a win-win all the way around.
I chose a straight over a double edge the day I tried the double edge. If I had tried the double edge first, there's no way I would have ever tried a straight. The DE offers everything I wanted when I wanted an alternative to cartridge razors: A way to shave that requires neither frequent nor expensive purchases of more blades every few days. But, I didn't know about DEs, and I was introduced to a straight. Having become accustomed to using straights, enjoying the shaves they offer me, and enjoying the mystique of owning and maintaining them, I no longer felt a need for what the DE offers by the time I was afforded the opportunity to try one.
I really enjoyed the DE process so much when I first got started that when I finally felt that I had it all figured out, I wanted to take it to the next level. Straight razor shaving seemed like a challenge and I wanted to take it on. I'm really glad I did. I'm still new at it, but every shave gets progressively more comfortable and I'm more and more impressed with the results as I become more skillful at it.
I started because of the coolness factor and because I am a tight ass. Continually buying those stupid M3 cartridges was making me poor. But now I continue to use it because its something I'm getting better at and I now look forward to shaving in the morning (I'm even willing to get out of bed a bit earlier to have the time to do it).