You've all read Sentry number 1, and Thunder bolts. Based on our current assumptions who wins. From what I’ve seen so far, Sentry has a clear power advantage but Photon has more effective powers. IMO you don't mess with anyone who can fold space and time as if it where a shirt. Speed wise these guys seem pretty even , i.e both are retively close to light speed, as they re fighting on earth they are unlikely to exceed mach 10.
Photon's Powers : Cosmic awareness (I.E. precognition that makes a Jedi night, look spaced out), nega bands seem to have a range of control over space time (i.e wormholes + Dimensional rifts) and photons i.e. used for energy blasts, and molecular rearrangement.
Sentry : Something to do with being out of sync with time ?
Vast Super strength (easilly able to lift an Oil tanker + over powered Terrax), Durability (Took on a full blast from Terrax ), control over hard light (anyone who reads Astonishing X Men knows how potent this stuff was, also note that he was able to take out the Avengers + FF4 + X men + Inhumans and others with hard light constructs. ).