Algeri isn't a major 147 fighter, he is a natural 140 guy and moved up to 147 to fight Khan and stayed there. Algeri would probably have usffered the same fate against Thurman.
Spence is a blue chip prospect, we don't know what he will do at the higher levels though when he gets there though so lets hold off a bit on crowning him king and let him show us if he is the truth.
That said there are a great deal of high level fighters at 147 with the current elite being Bradley and thurman right now. Spence keeps growing each fight, refining his skill and adding new wrinkles he'll be able to prove beyond a shadow of a doubt that he is what you and I think he will be.
Thurman wouldn't have dominated Algeri like that, he would've knocked him out like he the 8thor 9th or it would've went he distance. He would've got on his bike and survived, Thurman had trouble with Bundu's footwork and couldn't really hawk him down. Spence knows how to trap a fight and the body attack is what did Algeri in, something Thurman has already showed he could do consistently.
Collazo hurt Thurman to the body if that was Spence he wouldve been KO'd that round. Thurman is not durable enough to survive those types of shots for twelve rounds and he is not elusive enough to survive that type of pressure for 12 rounds. So he will have to Knock Spence out which means he will have to take risk which means he would probably get KO'd too.
The difference in power is night and day, Thurman's best win his Guerrero lets be honest. Garcia did the same amount of damage so their power have to be similar. Spence would KO guerrero or the it will be stopped because of damage.
Bradley is a non factor at 147 he's exactly how he described Algeri he is a 140 pounder who fought otehr 140 pounders at 147. Spence is a natural welterweight,he would fukk Bradley up. He's too small for spence or thurman, and doesn't have the boxing skill to make up the size difference so he will never fight any of them. He'll fight Vargas another 140 pounder for the the paper WBO 147 belt nobody gives a shyt about.
I think Thurman will beat Porter, score a flash knock down late in the fight but never really have him hurt.