I love practically all giant monsters, but I too can't say much Pestar's defense.
He's a unique idea for sure; a giant bat-headed Siamese starfish who drinks oil...but the execution is so poor that he betrays his own character concept!
It probably would have been better to drop the 'centerpiece bat-puppet', cut the suit in half, and have twin starfishes on the loose instead. But we also have to take into account the complete absence of ANY onscreen interaction between Ultraman and Pestar, which strongly suggest the effects staff couldn't find / afford a third suit actor for the climax. So a two-against-one battle at the end would have been difficult, to say the least.
I will say this in favor for the infamous Pestar - thanks to him (them?), we got a whole slew of two-guys standing side-by-side monsters throughout Tokusatsu / Kaiju history, all with varyingly degrees of success.
In my honest opinion, one of the better characters based on this design aesthetic was Antimatter from Ultraman Gaia, who was Pestar done right; both actors were perfectly instep, along with the inhuman design and impressive height for the suit, it truly felt like ONE whole creature.
Antimatter was a wonderful monster who secures Pestar's legacy, and in a positive manner at that.
And who knows, with all the surprised returns that Tsuburaya Productions seems to be excelling at these days, Pestar may return once more. And if all goes well, both the beast and we the viewers might benefit the better for it (never seen the Ultraman Powered episode, so can't comment on Pestar's appearance in that series).