6' 2" and 215 lbs.; do you know a bf%?

First off, 5 day splits are kind of a hard rut to get out of. With your experience there's no reason why you can't train a particular muscle more than once a week. Split routines are also detrimental because they make it hard to fit in the major compound lifts.

We'd really be able to give you better advice if you posted a real and full routine - not just "chest on monday 3x3" but like this:

MONDAY - Bench Press 3x5; JS Rows 3x5; etc.

Also: what you're talking about here is like a high-intensity regimen that turns INTO a high-volume routine. If you say most sets on the high-volume section are going to failure, you're probably doing too much volume. You don't want to trash the muscle to the point where you're not recovering in time for your next workout. You also probably have a lot more waste products than the average because of that (lactic acid etc.).

I would recommend dropping the volume, as high-intensity (low-rep work) is proven to be better at producing size gains, and moving into a full-body, 3-day-a-week routine if size is your aim. Something like Rippetoe's Starting Strength could be really beneficial here.

Just a few thoughts, hope it helps. Good luck.

-Cradler