definitely Lightbox!
I read some times ago that Eddie Van Halen himself considered Toto as the best musicians in the world, thus Lukather of course. said by Eddie, means something for sure..........
I could understand what EVH said = when you see ALL the studio works these guys have done with "everybody" !!!
And it's probably part of "too" much use of effects by Steve = don't forget it was the 80' and it was "One of the busy studio guy" ! And every producers probably ask him for effects ( remember the racks he had at this time !!! a studio even had to modify his door for that !!! )
With TOTO it was also the same story and had to use lot of effects. But YES, on his solo albums it's more "straight" sounds and now, it's more a (small) pedal board and an amp.
Not probably the "best" ( what this mean exactly anyway 
) and Yes Allan Holdsworth is more innovative and has impressive technical skill !
... NO problem, I like -and listen- both 
... let see what He could do with the Kemper in the next future ...
Hb 