Touring - Anyone using Sheldon Brown's Century Special cassette?

Ok so this is really for my family bike (I don't tour YET) but I am not really satisfied with the standard choices out there for 9 speed Shimano cassettes. I am riding a Marin Mill Valley (compact frame flat bar road bike) and often towing my son on his trailer bike and we have some (ok there is no flat here) hills so I some times feel like I am running out of gears with a 12-25 on the back and a road triple on the front (52/42/30). I know a couple of things about my riding of this bike (family and commuting riding) and #1 is that I NEVER ride in the big ring so I was thinking that I could switch it to a compact double if I could only find a cassette with more teeth in the lowest gears. MTB cassettes are an option but I don't think I need a 32 or 34 and I also would NEVER use the 11 and for that matter a 12 doesn't seem useful to me either which brought me to the Sheldon Brown and the Century Special which is 13-30. My goal will be to switch to a road compact double and change the big ring from 50 to 48 and have the small ring of 34.

So what is the quality of this cassette? At $100 (currently due to Shimano's lack of 12-27 supply) it is a little spendy but if it is going to last and is the right gearing then I am not so concerned about the price. Anyone using one of these and what do you think?

Can your frame and front derailleur handle a mtn bike crank? 22-32-44 or something like that would give you more usable gears. 44-12 is still plenty tall, and 22-25 might allow you to get buy without a new cassette. Alternatively, you could replace your rear derailleur with an LX mtn bike derailleur for not a lot more than $100 and get a low gearing of 30:34. $100 sounds pretty steep unless its DA, and then I ask, do you really need DA? Ultegra cassettes can be had for <$50 if you shop around.

Oh, and I believe he makes his cutom cassettes from shimano parts, so quality is similar to whatever grade shimano parts he uses. i.e. It should last 6000ish miles if you keep your drivetrain clean.

Not sure about the frame accepting a MTB crank but one thing I really want is to move to a double if I can. IMO I really don't need the 22 tooth granny gear just another gear or two on the back. Now one thing I might consider (if it will work) is going to a MTB crank with a MTB crank and the granny removed on a road double BB (for chain line), so that I can go like 44 and 32.