Filia is a good example.
@ashxu said she was "kneecapped", so let's take a look:
- j.HK is no longer an overhead. It still dodges throws and lots of ground moves, it's still 13f, safe on block and easily comboable off of, and it can still be a crossup after an IAD, and it can still be airdash cancelled for mixups afterward.
- IAD j.LK is now a reliable overhead that is
exactly the same speed as instant j.HK was and will hit every character crouching, but will not cross up and does not lead to airdash mixups afterward, and is a light attack which does less damage.
She lost an easy go-to tool that covered a great many options (fast safe overhead that could randomly crossup, led to multiple overheads, confirmed easily, hard attack combo starter, HCH, etc) in return for having to choose between two options that do everything she could before.
She also gained meterless throw conversions and much easier midscreen conversions with Ringlet, which improve it as a poking tool or in trade situations like incoming or antiair.
For having to think a bit more when you play her as opposed to just UF+HK, improved throw damage, and an improved midrange game, she got "kneecapped". That's what I deal with.
As for Double, you weren't really getting hit out of those 2 frames at the beginning of LK bomber all that often, so making it a legit DP doesn't really give her anything new. It's still got basically no reach and is ridiculously unsafe, and neither Monster nor Catheads makes it safe on block (Catheads gives a 26f gap IIRC before a head will hit you), plus it's 12f making it one of the slower DPs in the game. Removing MK bomber invincibility does a LOT in terms of helping the assist be less everything, but in return it has faster startup and LK can be invincible. Larger bullets helps Luger be more useful, but you can still duck the L version. H Luger makes conversions more reliable and encourages some non-barrel-loop combos as well as helping the assist some.
Again, all things you can figure out from the changes.