10 feet down with an intermediate line?!?!?!? Even at a full 1.5 inches per second, you are talking about waiting 80 seconds between casts!!!!!

Forget it, if you want to fish 10 feet or deeper, you need to be sinking at least 6" per second, or you'll spend 99% of your day waiting for the line to sink.

Personally, around 10 feet and deeper is when I break out the lead core. I have the patience to fish 30' max with that (about 40 seconds drop) but usually I limit myself to 20-25 feet down.

Also, a sink tip is never going to let you fish at 10 feet... unless the tip is at least 30 feet long. Even if you can get your fly 10' deep with a sink tip, two strips and you'll be back up to 6 feet in a hurry. Try it out in a pool sometime.