4-link coilover front verses leaf springs

My '77 CJ recently received a 6" rear suspension stretch using custom longer then stock leaf springs.  I didn't want to attempt a rear link suspension because I suffered through it once before failing to get it dialed.  I've also read more sad stories then successful ones on home built rear link suspensions.  This leaf approach on the rear is working fine, now I'm looking to the front end for another 6" stretch.

I spoke with a GenRight engineer at the Off-road Expo this weekend about their 4-link front kit.  He said the front 4-link is not as complicated as the rear as long as you keep the 3 control arms about the same length, parallel to each other and as parallel to the frame as possible. Same sort of suggestion for the track bar and drag link.  He also said squat or rise should not be an issue like I suffered with the rear suspension on previous attempt.

I also asked if there were any gains over front leafs. He replied:

1. Elimination of front end axle wrap really improved ledge climbing
2. Articulation gain is big (this I would believe)
3. Dual rate springs offers improved road and off-road ride
4. Highway handling should be about the same

So, is he blowing smoke up my back side just to get the sale?  

For the fabricators, what's your experience?  You don't have to inform me of the cost differences, I already know a link suspension is 3 times the cost.

Jeep Stat's:
'77 CJ5, 5.9L EFI V8, T98, Dana 18 with overdrive, 90" wheelbase going to 96", 62" wide Dynatrac D60's, 33" tires with axles geared for 37s.  I drive on the highway at 70mph, run easy trails, rock crawl, blast up sand dunes and down sand washes, and make annual Moab runs for the last 15 years.  What ever goes on this Jeep has to do it all.