The turbotech boost controller off eBay is great though, for the money you can't beat it.
Both Leech and I have noted that when we used the boost controller that even after upping the boost a little (I wouldn't do it too much on the stock turbo) boost was both smoother, and came on earlier than the stock solenoid. Well worth getting one.
Made a huge difference on my old S14 with nothing more than high flow turbo, tuned length exhaust manifold, and Blitz power induction air box. Using stock exhaust and everything.