All the combos of Professor William Webb are explained in the level 0 reviews. The review "olahren" made is very complete. This was 2 years ago, now, with The Scarlet Keys Investigators Expansion, Fingerprint Kit, Alchemical Distillation and even Grim Memoir made its appereance and Webb gained even more value because he can target more items with secrets/supplies/charges.
The weakness of the level 0 Webb is that, if you use this card as a sort of Scavenging for Seekers you'd lose at least 1-3 succesful investigate actions just for recycling items during the scenario. The upgraded Webb works the same but it has more sanity soak and an extra icon. The real upgrade of this version is that you still get a clue when an succesful investigation triggers this cards to recycle your items, so you won't lose actions. If you use Webb for his combo potential this upgrade means he won't slow you down, and Seeker class is all about improve action compression with and triggers using your EXP, so this is good enough for me.
On the other hand, if you play the "seeking for afar" archetype, this card does not improve the archetype unless you want to recycle items. Maybe Luke Robinson can use this to recycle the Grotesque Statue, since he has 3 and some token manipulation can make this kind of decks more viable for him on Hard and Expert Mode even with his small .
Webb (2) is Scavening for the Seeker class except for those seekers who have some sort of access to the Survivor class (Rex Murphy, Vincent Lee, Mandy Thompson and Minh Thi Phan). Webb (2) does not require to pass the test by 2 or more, so it is more reliable in Hard and Expert Mode. The other way to get 1 copy of Scavening for this class is paying Versatile, but your deck gets bigger and that can be a problem is you want to use specifically one or two items. Another problem of Webb compared to Scavening is that he uses the Ally slot, but playing as a Seeker usually means buying Charisma or Miskatonic Archaeology Funding to play two or three at the same time. The last problem of Webb is that he has limited uses, but all his recycled assets have major impact on the game and you can always run cards to forget about the secrets that also synergises with some powerful Seeker assets.
To sum up, Webb (2) can be good in some decks, but he is not an autoinclude nor and staple of the Seeker class. He has limitations you have to sort out to make him work. Even though, he is fun and I recommend to try him at least.
For me, Harvey Walters is a strong candidate to run Webb (2) in his decks since he can abuse the hell out of this card. He usually runs Miskatonic Archaeology Funding because he is very durable and he usually plays some Miskatonic allies in his decks, so Webb (2) ally slot problem is instantly solved. Webb (2) + Magnifying Glass is a good deck engine to discard and recycle your empty The Necronomicon and Ancient Stones.
On the other hand, I'd love to see some Joe Diamond decks using this in a cluever deck. He loves the 3 horror soak of Webb (3) because of his poor Mythos defense, and the possibility to recycle Fingerprint Kit 1-3 times during a scenario doing the Magnifying Glass discard tech sounds good! If you manage to get your Detective's Colt 1911s on the table you can even play a Hawk-Eye Folding Camera to enhance your while cycling through the Magnifying Glass and the kit. The only problem is the money, so you'll need to run cards like Crafty, Burning the Midnight Oil and Crack the Case or even running Charisma + Dr. Milan Christopher. He can also "Webb recycle" the Police Badge to support other investigators or cycle through 2 copies of Eon Chart with his good enough card pool.