I don't think you've given us enough information to give the best answer.
In terms of basic quality, I would say that S&W is a better quality gun than Taurus. I base this on the opinions of my old pistolsmith Teddy Jacobson who has worked extensively on both brands, and also on the opinion of Grant Cunningham, a well known and respected smith who works exclusively on revolvers and will not work on Taurus revolvers, as he feels their parts quality makes it too much of a hassle to work on them. My personal preference would be a pre-lock, pre-MIM parts S&W.
In terms of caliber, bigger is better although with the best modern bullet technology, which is more available in .38 Special than .44, the difference is minimized. I think the general consensus is that where you shoot the bad guy is more important that what you shoot him with.
No question, however that the.44 will kick your hand harder than .38. The question of whether this will adversely affect your ability to shoot fast and accurately, and how much, is a question only you can answer, and revolver weight plays into it also. For example, I have shot the Smith 642, Smith 640, Colt Agent and Colt Detective Special with .38 Special +P and I personally find that even from a rest, the 5 shot groups with an alloy frame revolver are about 50% larger than from the equivalent steel frame version. The most likely reason for this, other than the general unpleasantness of the recoil, is that the light weight leads to a stiff recoil which tends to magnify any variation in grip. Perhaps that is not true with others but it is with me and has definitely affected my choice. With the 640 or the Colt DS I have shot less than 3" groups at 25 yards from a rest but I find the Colt easier to shoot well, so that is MY first choice based on MY ability and experience.
Also, you have not stated whether you are choosing for home defense, concealed carry with a holster, pocket carry, etc. Obviously for pocket carry the Smith 642 is a logical choice, being the smallest and lightest (again, assuming you can shoot it well). However for belt carry with a holster a revolver with a 3"-4" barrel makes better sense. The longer sight radius makes it easier to achieve practical accuracy, actually helps with concealment by giving a bigger lever to push the butt in closer to the body, and dampens recoil a bit allowing faster recovery for follow-up shots. With a good holster and belt, a 4" revolver is as easy to conceal as a 2" revolver. Remember that many experts have stated that a short barrel handgun is one of the most difficult to shoot well and requires the most practice. That means that it is definitely NOT a good idea to choose a handgun that you find unpleasant to shoot and therefore will not practice with.
So if you haven't shot either of your choices you should make every effort to do so to see how you feel about them. It may be that after you shoot both the choice will be obvious based on YOUR comfort with the recoil and YOUR ability to shoot them. Or, it is possible after shooting them you may not feel comfortable with either and will want to expand your options. The takeaway point is that since it is your neck that is at stake you should try your options yourself and make a decision based on what is most comfortable to you based on your experience in shooting them, and NOT on the opinions of anyone else, no matter how experienced or well intentioned.
