I shaved two days ago and my shave today is still closer than what a Mach 3 can do.

If you are getting any irritation with a straight razor you are doing something waaaaaay wrong.

During your learning curve you are going to have lots of days when you wonder if you should stick with it. First, you'll probably stick with it for the cool factor, next the skin care factor, after that the closeness. In the end you'll probably be left with only two factors. Do you have the time and are you willing to focus during your shave. Those two factors can never be truely removed. You won't need to focus as much later on as you do now, but you'll never be able to shave with a straight while you intently think about something else. Some people love this aspect of shaving, some people don't.

The only reason not to shave with a straight razor is if you're not willing or interested in putting in the time to learn, or if even after you have put in the time, you are not willing to focus or spend the extra 10 minutes or so to shave (keeping in mind that you could get by only shaving every other day with a straight). Then, by all means, use whatever works best for you.