So I have had the issue of deciding about hi intensity running/biking.

So currently I have 2 high intensity biking sessions a week 1 is subthreshold (2x15' <100%FTP), the other is post-threshold (2x15' 110% FTP/LTHR).
I have 1 strength workout which could be considered threshold but I dont hold it long enough to be that.
I have numerous base rides as I do Brick workouts regularly. But in particular I have 1 long ride a week, and my warmups are about 1-2 hours before I hit the switch.

Now, I have speedwork I do off the bike (running) as well, mostly progression work, 4x400meterx2' chill for a few then 2x800meterx2' chill for a few then 2x1mile with 5 minute.
I have 1 tempo run ~30 minutes. 1 repitition run (stride repeats with long recovery), 1 long run and 3 or so 15-45' base runs.

Most coaches do not recommend more then 2 bouts of LT work a week, I consider this to be only 2 high intensity work, and my LT work is less then the recommended allowance of 40 minutes (on bike).

I want to have 1 more day of speedwork off the bike, how should I go about doing this, Long Recovery intervals? mainly I want mile repeats 5x5x5. and just make it 5x5x10? I heard long recovery is alot less stressful then shorter recoveries but the gains are less.

SO what is the difference between running and biking? can anyone shed some light on the "Art of Peaking" for duathletes like myself?

Please do not recommend coaching, I have gone through a half dozen in the past few years and have come to the conclusion that unless you develop an intimate relationship, your nothing more then a guinea pig or a "Copy and paste".

Thanks guys