I was raised with the adage of 'always use a heavy iron - let it do the work for you'. I've been using Rowentas for many years now and not had the issues most here have so I'll stick with them.
I also press almost all of my seams open. So I (like you) set the seam first then press the seam open from the back and finally press the unit from the front. I also use steam religiously. All this probably stems from my early sewing of garments vs anything else. I will sometimes get that little pleat on the front as well but then just press the heck out of it. I don't use a clapper but have thought sometimes a ham might be a handy tool to own but have not been so compelled to actually buy one yet.
Do you use starch? I use the liquid starch (usually sta-flo) that you can mix to varying strengths. I usually do a 50/50 mix and find it works well. I believe it helps with not only cutting, but pressing as well. I will also admit to 'ironing' vs 'pressing' frequently. Between that and steam, if my unit/block gets a little distorted, I will trim to the correct size before moving on.
All of the above are very tedious processes but I do believe it makes for a better quilt (or any other sewing project for that matter). And yes, I do it for each and every seam I sew. I am a far cry from a perfectionist. I do find that it makes the next step in my project easier to manage.