Some other criteria I would add for handguards is whether you’re suppressing or not, whether you want to sleeve or not sleeve, or use a bipod. So the decision tree for me goes like this:
Does it need to be rock-solid for a forward-mounted LAM or clip-on TWS?
If not, will it be suppressed and sleeved or the suppressor in the open?
Will it have a bipod mounted frequently?
Is it primarily a target rifle or HD/CQM blaster?
For a target rifle or varminter, it’s nice to have a rigid handguard that minimizes flex input from a bipod or bag up front.
For HD/CQM, I prefer lightweight and enough real estate for the barrel length.
A lot of the lightweight & slim handguards made over the past 15 years don’t do well with mounting bipods, so it’s something to think about.
These slim MLOK tubes almost always require you to get another mounting point to attach to the bottom for bipod QA/QD, or stud attach.