The OP is seeking the "best performance shock" (excludes TD IMO), but has a beer budget (cue TD).
Pardon me if I take that with a large grain of salt.
I know of one suspension engineer (products well known to ih8mud) in Aus who stocks and sells EFS despite his own opinion of the product being extremely low, but many customers won't be talked out of buying them in favour of a less heavily advertised superior product.
I've had EFS shocks on a rig as a cheap stop gap for completely shot shocks (few options in the length I needed).
Putting TD in the same category as EFS is an interesting selling point
Well I'll take your post with an even larger grain.... Anyone that has that kind of knowledge/experience as a "suspension engineer" that can't tell a customer NO is only about making a buck, IMO... Otherwise the "inferior product" would NEVER be offered from an ethical business person that was truly about quality and service from 25+ years of usiness experience. But, I'm sure the EFS owners/team would like to know this info.
As far as putting TD and EFS in the same category... That is several of your Aussie vendors/re-sellers responses. I've never run a coil system of EFS', but I have run a leaf spring system and I'll agree with their assessment. I'll always trust a NON-competitors opinion over a competitors or a competitors spokesperson.
I can tell everyone this, I have sold exactly 183 complete Tough Dog kits for 40, 60, 70, 80, 100, 200, E-Hilux, Land Rover D1, D2 and D110, Frontier/Navara, BT-50 Mazda, Jeep Wrangler and Ford Rangers with exactly an additional 143 pairs of shocks sold separately since May of 2016. I have yet to have a return for warranty or any mechanical failure or complaint. I have kits and components from day one install to 26K miles from Tough Dog. The only complaint I've had on 4 occasions is that the lift was taller than advertised; 2 on 80 series and 2 on 100 series.
If anyone has had an issue, it was never reported back to me or Tough Dog. I'm all over MUD and 9 other forums with an exceptional CS and product reputation and response time (less than 24 hours, yes I pride myself on this)
Also, I have a ZERO customer base with incomplete, missing or damaged pieces on full kits from Trail Tailor or Tough Dog since I have been the N.A. distributor. My order received to ship date is 48 hours at most (if they order on the weekend) on stocked items. Custom orders are less than 2 weeks if not in stock. Once again due to Tough Dog's excellent service and inventory control in Blacktown.
I'll stand by what, has so far been a 100% satisfied customer base (306 total customer orders, some repeat).
Have a nice day,
J