All of my rifles are extremely fast, have lights, optics and sometimes lasers.... All are well under 9 pounds, usually a good bit less, even with the ACOG or a T1 and a suppressor. It's just as handy if not handier because now I can see.
If I need light and full auto, I have an mp5 for that. I'll still take an equipped S/A carbine any day of the week. I can't see any argument against using things that make you a better shooter, whether at home, in country, when teaching or training, or on a flat range. The only valid arguments I sew are - I can't afford it and I don't shoot enough for it to matter and won't spend the time training.
If I wanted to save money I'd have found a different lifestyle...
Right that this thread was about training, then comments were made about junk being added and other similar things that really don't make a lot of sense for those reasons. I will buy anything that's quality AND will give me an advantage....plus I still train (not just shoot) three or four times a week.
Lumping all the accessories together as useless, for mall ninjas and whatever other comments were made isn't something that would come from most serious users/trainers/students as they'll all see the true advantage. If they don't, the range time and ammo is on me and I'll be more than glad to show them the differences at my cost.... Military, close protection, competition or weekend dirt shooter.