Westside's really advanced and requires enough experience to know what you need and how to do it without overtraining.
DFT depends on you. Definately NOT advisable for you to do the advanced version of df 5x5 as I've done a few times. However, you seem to have really liked/reponded well to Mark Rippetoe's starting strength. So why not take it up a notch and do Single Factor 5x5, which is the next step up from that beginners program you've done some time ago?
So my vote is to stay away from Westside, but embrace Single Factor 5x5..Which you can do successfully for quite some time until customization becomes paramount.
Additionally, single factor 5x5 does NOT require a deload, which IMO isn't what you need.
And I understand what you're saying about HST being a tad bit boring. Submaximal weights usually are. If you are looking for an optimal route to mass gains, then I'd repeat HST. Otherwise, there's still a great deal of mass to be made with SF 5x5.