You know, for just a simple little computer, it sounds like it's quite accurate! Certainly much more realistic than various iPhone apps and many other devices. Ultimately, even if it weren't so accurate, I think the important thing is just having something consistent that you use all the time to compare each ride with other rides, so that you can see that you're making progress (even on days when it doesn't feel like it).

As for the speed- it will come, as you get stronger and more fit. I can vividly remember my first "real" ride when I started cycling last April: An 11 mile loop, which took me an hour and 20 minutes. I had to stop and rest halfway up just about every hill; and then again, when I'd get to the top of them. I was huffing and puffing so hard, I thought I was going to die. Progress seemed slow....I struggled on the hills for a long time; I did get a little faster- but kept struggling; and even though I gradually upped my rides to 25 miles, I never seemed to get much faster.....

But just recently, seemingly all of a sudden, I've gotten to where I can whiz over all but the biggest hills- and I'm realistically averaging 15-16MPH now, which is a 50% improvement. I'm like you, in that I could care less about racing [and I ride solo, so keeping up with others is not a concern], but I do want to be relatively fast, so I can take a 25 or 30 mile ride in a reasonable time- because the 2 hours that my average 25 mile ride was taking, was just too long.

So hang in there and don't despair. [Getting an indoor spin bike to use during the winter when I can't ride much, seemed to really help me...as i tend to be lazy on my road bike, because I look at it more as enjoyment than exercise- but on the spin bike, I push myself, because I "want it to count". It was just after getting the spin bike that I saw my road bike performance make a dramatic leap.]