I've been playing a few adventures and I see that with just a single metamagic I'm much stronger and more effective than any other caster... applying disadvantage to ALL saving throws and also increasing +1 DC (equivalent to +2 attribute) makes me incredibly effective and hard to beat.
First, to clarify-- heighten spell applies disadvantage to ONE saving throw, even if multiple entities are making saves. So it decidedly increases the success-likelihood of a
Counterspell, but only marginally increases the overall success of a well-used
Fear, Hypnotic Pattern, or multi-target
Hold Person (admittedly, if you were to use heighten spell on such a multi-target spell, you would give disadvantage to the target you most want to fail the save).
There are spells (single-target lockdown) where it is decidedly effective. It needs to be noted, however, that 1) situations where locking down a single target has great influence to the overall outcome are a subset of overall situations, and 2) -- those spells were already highly effective in those situations (Horwath is correct that it is simply moving the chance of success from X% to Y%).
Regardless, those are often clutch situations, so the ability
is powerful. As it should be, given that metamagic is the biggest thing sorcerers get, and there are other options like Subtle, Careful, and Quicken that can fundamentally change when you would even consider casting a spell to begin with. Really it is metamagic abilities like empowered (switch 1s on damage rolls for avg 3.5 most of the time) that seem to underperform.
Innate sorcery is more interesting. In boss battles, its use seems clear, although at times the bonus action to invoke is a hard choice between other things people want to do round one. In other situations, I've tended to see people decide to use it about one round after it would have mattered.
Regardless, it actually matters one roll in 20 (or just a little more than that if we go by checks instead of rolls and dis/advantage is on the table). As the math thrown around every thread about ASIs/starting-at-16+ have shown, that's super-not-nothing. At the same time, for a game that can work with both rolled stats and point buy/array, we also know it's not the end-all and be-all. So again, the effect is powerful, but should be based on how much of the class features it represents.
In both cases, I don't see it making sorcerers "the most powerful today." It's an effective use of class abilities, full stop. And kudos to whomever played around with it and recognized that it was effective. But that's it. It makes effective strategies (which already would have been powerful) that much more so.
