nanney1, you said you've shot both the Shield and the 637. How many rounds have you put through the 637? I've noticed when I let people, even experience shooters try my Airweight j-frame, they like the first cylinder. By the 2nd they're starting to think that it kicks, and rarely does anyone go past a 3rd cylinder. Heck, I love shooting my 442 but I rarely go past 50 rounds in a range session before I start to feel it in the meat of my palm.
Just something to think about, because the Shield will probably be more enjoyable to shoot at the range. Personally, I love my revolvers and carry them more than my single stack 9, but I'm not sure an aluminum framed .38sp is the best option for a 1st gun. The Taurus 85 may be better, even with the risk of low quality. Or a S&W 640 or SP101 if you have the funds for something more expensive.
If you stick with the Airweight, I'd recommend the 642 or 638. Those tiny hammers of the 637 can snag, and covering the hammer with your thumb when you draw isn't always practical. I carried a 337 for about a year before putting it in the safe and now I carry a 442 most of the time.