Originally, Sunspot's superhuman power was limited solely to superhuman strength, and then only in his solar form. Unlike many superhumanly strong heroes, Sunspot was unique in that he had no superhuman resistance to injury, and was not bulletproof by any means. The phrase, "Careful Bobby, you're strong, not invulnerable!" in its many variations became as much a Claremont catchphrase as Wolverine's "I'm the best at what I do!" The degree of Roberto's strength level has not been firmly defined - sources such as the Offical Handbook to the Marvel Universe cited his solar strength as ranging from anywhere between a 2-3 [ton]s, to a 20-30 [[ton] level. It is likely that his strength level was at the lower range initially, increasing as his experience and training grew. In addition, Sunspot's powers have radically changed and grown since the character was introduced, and whilst his power augmentations have concentrated on areas other than his strength, it is feasible that his strength has increased still further.
Dude. I love Spiderman, but Sunspot would curbstomp him so bad, it might be considered a hate-crime.
Sunspot is not a street-leveler by any means. The longer stays in the sun, the stronger he gets. And he can store his energy to use it at night. He is UBER powerful, able to fly, superhuman reflexes and speed, superhuman strength (class 50 I believe), and can fire energy blasts from his hands.
I love Spidey, but Sunspots thrashes him pretty badly.