I have a couple of 642's that still get shot a good bit, but not carried to much anymore these days. They are still my favorite "carry" snubbie. I never really carried them IWB, unless they were just stuck in my waistband, sans holster. My normal carry mode for them is either a Desantis ankle holster, or a GALCO "Executive" shoulder holster, both of which, work very well. A Desantis "Confidant" undershirt holster also works very well, and with the pair together.
Ive had a number of others, mostly all Smiths, 10's, 60's, 637's, and a 19, which I still have. The J frames were carried in the same holsters above, the K frames, on my belt, in a leather OWB.
The K frames are the most pleasant to shoot, but not necessarily, pleasant, especially depending on what grips they are wearing and the load. The light J frames are not pleasant, especially when wearing "carry" grips (for me, thats the old service stocks and a Tyler T grip), and anymore, about a box of 50 is all I can take at an outing.
As far as removing the spur on the trigger, Ive done it on a couple of K and N frame guns I converted to DAO, and never had an issue with ignition. I didnt remove anymore material than was necessary to get a smooth job, and more or less pleasing lines. Ive seen some that literally looked like a hack job.
If youre shooting them as they should be shot, there really is no need for the spur, the lack of it, does aid in getting it out of snaggy places.