There is nothing wrong with splits. Its just alot of people pound there muscles into suBathmateission. like 10-12 sets just on chest ect. Even with a weeks rest thats still too many sets. If you over work your muscle it will stress itself more on just repairing the muscle and not making it grow(unless your on steroids). Ive learned that less is more. I've read that out of ever set you do, its ultimatly the last set you do that will give you the results and it only really takes 1 but there's nothin wrong with more. My old trainer told me that Full body workout are better to build a base and overall mass. once you've developed your whole body then you should do a split to further develope your muscles to get closer to your genetic limit. plus splits are better for working on lagging parts.
As far as super setting goes, I work 2 different muscles in the set, chest then back, and quads and hamstrings. I never superset say bench with flys because it not really productive (for me), it will just make my chest sore. But i do dips once in awhile whic i know is a chest exercise but it will work your arms more if you keep your self upright. Super Sets also save time plus gives you a great cardio work out too (just dont go soft and use lighter weights). After Squats Super setted with DL im breathing very heavily and i often rest an extra minute to catch my breath. I like the idea that im working the same muscle 3 time a week and i dont over train because im not pounding them. That and if you do 3 sets in strait set form this routine will take longer than a hour and thats counter productive.
In the end its a matter of preference but full body workout's are alot better for me and alot of people i know for fast results. Its good for beginners because it teaches your body to work as a unit and a good way to work on form. I still do splits once and awhile but i never get the results i get with full body. Plus i tend to have a better appetite.
As far as rep range, yes i also lift heavy too. Ill do 15 rep range one week then 10 rep range the next and 5 reps the next after that. with 5 reps i do extra warm up sets to prevent injury 4x5 or 5x5. you could also do all three in one week ...monday 15 wed 10 fri 5. i just get better growth at 10 reps. they say lower rep(4-6) are better for strength and higher are better for hypertrophy (8-12). Althogh i upped my bench 25 lbs in a month a 10 reps.
No matter what you do after 6 weeks you should take a week off or after 12 weeks take 2. your muscles dont grow in the gym, they grow when your resting. I love taking weeks off b/c when i go back to the guy i feel like and anilmal plus im usually stronger. both styles have there advantages and disadvantages. But full body works for me so ill stick with what works.
