I have done a couple Flash Fire, and DMO builds on a couple of accounts.
No Wizard build IMO compares to the T10 clearing speed of Flash Fire in normal rifts. It just gives you the speed that you need and over the TOP DPS for T10. It can be a little squishy depending on your gearing.
However, you will quickly hit a wall in both survivability and overall DPS in higher GRifts... Once things aren't blowing apart as soon as you get within Explosive Blast range, and you actually start taking damage from higher GRift mobs...You will see the problem. I will point out that it's a great way to speed clear low GRifts to get the base levels of your legendary gems filled.
If you are solo botting a wizard and want to get high GRifts, DMO Arcane Orb is the way to go. I have done many experiments, including side by side testing builds on multiple bots against other DMO builds. It's just the best overall for botting GRifts.
In terms of speedruns on T10 rifts, you can change out gems, skills and cube items to jack up movement speed and cooldown reduction on an Arcane Orb DMO wizard and get some good clear times. A big limitation compared to flash fire is the smaller AOE distance, and the internal cooldown on arcane orb explosions. If you can only gear one build for both Speed Runs and GRifts, Arcane orb can work, but Flash Fire is just so much more melty goodness for T10.
Last but certainly not least is the Energy Twister DMO Wizard. ET DMO is best for group play.. but only if you have globe support characters in the group. This is due to the synergy of an ET Wizard and health globes dropping all over the screen. Everytime a globe is picked up, you get a free cast of Energy Twister. I have seen people pull off one ET + one globe support, but you need to watch your gearing on the Wizard to make sure you're not running out of mana. ET is NOT suitable for solo botting when compared to Arcane Orb DMO. The twisters are just too unpredictable and the DPS is too unpredictable. I also find that the bot dies more when playing ET.
All of that said, these are just my opinions. I have used wizards on 3 accounts, and done many tests.
If you are going to multibot, my best group was ET Wizard + Globe Monk + Globe Barb + LoN Crusader. ET Wizard + ET + Globe Monk + Globe Barb performed okay but not quite as well as the first group. These performed much better than any permutation with an Arcane Orb Wizard. Using Arcane Orb + Arcane Orb + ZDPS Monk + LoN Crusader was much slower. ET + Arcane Orb + Globe Support + Globe Support was in the middle but I seemed to drag a lot more on tough enemies.
I am currently in the process of finishing gearing 4 LoN Crusaders to see how they compare when multibotting. So far with sub-optimal gearing, it's pretty consistent with the ET + Monk + Barb + Sader.
Hope that helps, just my personal experience.
