Naruto - Chapter #674-675
"If he'd been born earlier than Obito, I'd have..."
"You did exactly as I'd intended... exceeded my hopes, in fact."
If Madara regrets choosing Obito and wishes he could've chosen Sasuke instead, why would he say Obito exceeded his hopes?
Did he mean that Sasuke was equally as "desirable" as Obito, hence if he'd been born earlier, not around the same time, he would've chosen Sasuke? (If born around the same time, it would've been a toss-up in hindsight?)
Actually, why would he even say Obito "exceeded his hopes"?
Obito needed 17 long years to capture the bijū, which Madara clearly disapproved of.
(Chapter #659 - "Don't compare me with that brat who took years...")
Obito also needed the Akatsuki for this, seeing as he waited 15+ years to even start collecting the bijū, which many readers excuse as time that the Akatsuki needed to gather funds, increase their standing in the shinobi world, etc.
But based on his feats alone, Obito should have been able to easily collect all the bijū on his own & complete the plan long before Naruto even started:
Obito should already know Naruto was the new jinchūriki, and even if he didn't, he could've figured out every jinchūriki's location & identity within a few years at worst.
He had at his disposal White Zetsu, who could be cloned to infinity, and could perfectly impersonate anyone down to their chakra signature that even high-level sensors could not detect them. They should be the perfect spies to infiltrate any village.
Not to mention, the identity of every jinchūriki seems to be an "open secret" as we see in Naruto & Killer Bee. Unlike Bee, most of them also have little to no protection: Deidara said they were able to take 2 jinchūriki without a fuss before Gaara.
(If the Akatsuki were worried about calling attention to themselves by swiftly kidnapping jinchūriki, they could've left behind a White Zetsu as a double, which should hold for days if not weeks; long enough for no alarm to have been raised until all the bijū were already sealed.)
And with his Kamui, MS genjutsu, and Mokuton, Obito should've had no problem kidnapping every jinchūriki:
With Kamui, he could teleport anywhere, bypass any security measure (as he did with Konoha's barriers), bring anyone to his own dimension where they'd be helpless to his genjutsu/chakra-absorbing mokuton—with one touch & within seconds (as he did with Fū & Torune, who were said to be the best of Root ANBU: the elite of the elite).
With his genjutsu, Obito was able to turn Yagura, a perfect jinchūriki, into a puppet, which might scale this feat to equal if not above Kotoamatsukami. Even Ao & Mei thought it was Koto, when in fact it was Obito's Sharingan: Eye of Hypnotism.
With Mokuton, Obito could restrain bijū and absorb their chakra, just like Hashirama and Yamato, who only reached a fraction of Hashirama's power per his own admittance (and thus has a visibly different form of mokuton).
Yet for some reason, Obito failed to use all these abilities to complete his plan.
(Some theorize that Obito subconsciously sabotaged himself, hence all his doubts even during the war & falling to Talk no Jutsu.)
(We all know the real reason is plot.)
But worst of all, Madara had trusted Obito to revive him when the time was right, yet Obito clearly never planned on following through with that. Without Zetsu & Kabuto, Madara would have remained dead and rotting somewhere.
Either way, Obito's "performance" as Madara, which undeniably placed the Eye of the Moon Plan in limbo (no pun intended) for 15+ years, should not have warranted Madara saying that Obito "exceeded his hopes"—unless Madara was merely referring to how OP Kamui turned out to be.
(Even Zetsu knew this and was displeased by how Obito "went against" Madara's plans.)
(Chapter #657 - "He's a good-for-nothing traitor who went against Madara's plan.")
So why did Madara say this, and mere moments after implying he wished he could've chosen Sasuke instead of Obito?