I use an ATTY, but it's scratchy at low volumes and the mute button has been broken for years now haha.

I haven't actually looked into this for a few years, but now I'm looking to upgrade/replace my current controller.  What are you guys using for volume attenuation/speaker-switching/etc nowadays?

SMPro Mpatch2.  Works great.

I didn't really delved into this topic too far since my Focusrite interface fortunately came with a monitor level knob built in and perhaps it will not suit your needs but the one that seemed to be the most cost effective and got consistently good reviews when I was in the market for such a device was the Mackie Big Knob.

The feature set of "Presonus Monitor Station" (not the same as their more expensive Central Station) has about everything you could ask for (besides a quality build).  If it was higher quality it would be the perfect unit.
 
I've heard more bad than good about Mackie Big Knob.  The [class="productnamecolorlarge colors_productname"]SM Pro M-Patch 2 sounds nice, but I would personally miss the extra headphone amps + talk-back.

 
You can get into another class of controller above this price range, but you will find that the price gets steep while features drop off.

I will retract my endorsement of the Mackie Big Knob series if there are indeed known issues with it. It was just one of the devices I had widdled my list down to before receiving my Scarlett and realizing I didn't need a monitor level controller.
 
Actually I think bapu pointed me to some simpler and less expensive devices... lemme check my bookmarks...
 
Ah yes... I think this is the one... but perhaps not...
 
http://www.musiciansfriend.com/pro-audio/sm-pro-audio-nano-patch-passive-volume-attenuator
 
SM Audio Nano Patch. You might need something more elaborate though.
 
i'll shut up now...

This is one of those topics that people have huge, open opinions about.
Active vs passive, number of monitor-sets, need for a sub-monitor out, heck even rackmount vs desktop.
 
I used a little ol' ATTY (http://www.adesignsaudio.com/atty-stereo-attenuator.htm) for years now and it's been ok.  I figure my next controller is bound to be an upgrade.
 
Before the market was full of these types of things (over 5 years ago I think now), I actually had a company designing me one based on my specs.  Was such an awesome unit.  However, that kinda got washed out over the years and now I'm out a good amount of cash :p
 
All well that ends well!

  I have a Focusrite Pro40. Maybe someone that knows can answer this question.
  I been told that the volume control on the Pro 40 reduces volume digitally, which reduces bit depth and an analog volume control will reduce volume without reducing bit depth.
  Is this true and if so, would it be noticeable.
  ( sorry if I'm hijacking this thread)

I just use a TC Electronic Level Pilot since I don't have any need for switching.  Quite happy with it.
 
http://www.tcelectronic.com/level-pilot/
 

I use the Mackie Big Knob.
I've read that it may or may not color the sound but if it does, I trust ARC to compensate for it.

Hi Joeb - that's what I've been told (both by folks on here and the guys at Robotspeak in SF) and it's why I got my Level Pilot.  Also, that seems to make intuitive sense to me.