Spence has promise but he is fighting low hanging fruit at this point. I understand he wants to fight often but Vargas wasn't very good to begin with and had a week to train. Spence needs to move up in class and fight some decent fringe contenders or old journeymen instead of fighters losing to them before talking about Thurman.
The Roberto Garcia fight is a good step up. If he can take care of him in impressive fashion, he'll be ready for the big time
Being a sparring partner for Manny does not mean that he is a serious threat to beat one of the best in the division in Thurman. Gomez has the potential to be a serious contender but potential is only realised when the fighter in question steps up to world class level. And enough great prospects have failed to advise caution with regards young Gomez.