I'm sure there's a few over 500 now.  The theoretical max is well over 500 

I don't pretend to be a top-end speedster in Raid.  My two fastest toons are (only) around 360, and that does sometimes feel slower than ever.  

I don't have anyone above the 340s ...

5 pieces of gear, quad role mythic speed: 36 * 5 = 180

6* boots, speed acension: 45 + 12                       + 57

banner, quad role mythic speed                           + 36

6 piece speed set, 2 piece feral: 36 + 10              + 46    =319

Lore of steel  (180+57+36+46) *1.15                                =366.85

Area bonus great hall                                            =20

+4 empowerment                                                 =15

6* lego blessing                                                     =15

 Total WITHOUT buffs, aura, passives                                =419.85

On a champ with a base speed of 110:                              =529.86

Speed aura + 6* intimidating presence:         [up to] 54

Speed buff, masteries like whirldwind of death                  =700+

Did I miss anything?

First, Your Lore of Steel calculation is not accurate.  Lore of Steel modifies only the increase of speed for the gearset bonus, not all of the speed from the substats, so:

(1) 6 Pieces of Speed gear on a toon with 110 base speed is:

• 110 x .36 = 39.6
• 39.6 x .15 = 5.94 speed bonus from LoS

(2) 3 Protection Accessories on a toon with 110 base speed is:

• 110 x .12 = 13.2
• 13.2 x .15 = 1.98 speed bonus from LoS 

Maximum speed bonus from Gear is 50.8 and from LoS is 7.92, for a grand total of 58.72.

Second, you missed Faction Guardians for +10

Third, this started as an Live Arena Example, and there is no Area Bonus for Arena, so -20

Fourth, Glyphs will be 6 x 8 maximum additional speed:  + 48

you appear to have left out the glyphs, so that's another 48 right there.

you've messed up in applying lore of steel though, so that's pushing the total higher than it should. it only increases the set bonuses by 1.15, so that'll only add another 5 or 6 speed to the total (speaking of set bonuses, you'll get more speed with 6 piece speed, 3 piece protection).

Yep, you both got me, completely missed glyphs, messed up some of the other calcs.

Still, it's quite *possible* with absurd rolls to get a champ to well over 700 speed

Zzz... meanwhile my arena teams are at 130 speed :)

I can get over 400 but I think the fastest practical champ I have is Basher (my lockout king) at 385 or so. Most of my nukers are 200-220ish, supports 270-290 (with obvious exceptions)

only thing I'd say is 3 Supersonic accessories would be 10% more speed, since 2 feral accessories would be 5%

EDIT: Actually scratch that, 3 Protection Accessories would be another 12% so that's even better

Can't wait for you to pull Yumeko and Warlord this weekend.  #JustThorneyThings 

Pft you probably just jinxed him, now its gonna be 9 Harriers and a Angar

That's not how it works for Thorne. You can't jinx him, his luck is stronger than any jinx.

I'm expecting a +4 basher and some combo of Warlord/Yume/2nd Narses/Odin/super murder Shadowkin guy by the end of the weekend :)

Oni is unfamiliar with Thornes power.  The more you try to jinx him the more lucksack he becomes.  Hate fuels him, he's a true Philadelphian.

If you don't you owe me and Q each a Harima.

Well at least he gets to shop at WaWa sometimes

So I just asked on LIVE chat what you all stated and the EXPERTS  just stated  (Experts being top Live arena champions META)

510 will be max speed anywhere in the game

Just saying

I am subbed to soooooo many  YouTube CCs  = its the only  TV  I watch ...so to speak

I mean that's mathematically wrong on its face.

115 - Base Speed
57 - Speed Ascended Boots ( 45 + 12 )
48 - Speed Glyphs ( 6 * 8 )
216 - Speed Rolls ( 36 * 6 )
55.2 - Set Bonus ( 5 Prot + 4 Speed )
8.28 - Lore of Steel ( 48% * 0.15 )
15 - 6* Awakening
10 - Full Faction Guardians
15 - +4 Empowerment

539.48 theoretical max

I can only report on what the EXPERTS tell me and I am in no way an expert of this topic.

Not disputing what you say.

Just telling you what the BEST in the game who are Ranked number  1  in the World tell me :/