Lightroom 5 Spot Removal Tool Lags and is not usable (Temp Workaround?)

Question

Lightroom 5 Spot Removal Tool Lags and is not usable.  The Spot Removal Tool really is pretty essential to the usability and workflow of Lightroom 5.  Checking the other tools alongside the Spot Removal Tool, it appears that the Red Eye Correction Tool is also affected.  Might it have something to do with the Process Version?  I noticed when working with some older image files (using the 2010 Process Version), the Spot Removal Tool worked as previously experienced. Current images that have been "upgraded" to the New Process Version (2012) are now incapable of utilizing the Spot Removal Tool due to its very laggy and sporadic response.  I've never experienced an issue like this with Lightroom (LR user since LR2).  Mac OSX 10.7.5, 3.4GHz i7, 8GB 1333MHz DDR3
I've also noticed that reprocessing an image can revert the Spot Removal Tool to "useful" again (reverting from 2012 to 2010, then back to 2012).  Doesn't always work and doesn't always "stick", as closing and reopenling LR usually reinitiates the laggy Spot Removal Tool.
I haven't seen anyone mention the Process Version as a potential culprit, nor have I seen any reliable workarounds.  Reprocessing an image (or set of images) at least works for me for a while, though it would sure be nice to not have continue reprocessing images every time I open/use Lightroom 5.
LR5 is great and is all I need for the majority of my images.  Unfortunately for me, though, that usability also necessitates the Spot Removal Tool's unhindered functionality.

Answer 1

For some reason, it's clear that not everyone is experiencing such a massive slowdown / bottleneck when it comes to the Spot Removal Tool.  If all users experienced this issue to this degree, they would have been clamoring for Adobe to address and rectify it immediately.
With all due respect, Sean, to make a suggestion like that proves you do not experience / have not experienced this issue / don't understand the severity to which this issue can affect workflow; simply "turning off noise reduction and lens correction" is definitely not a fix.  If 16GB of RAM doesn't fix the issue, do you really think simply turning off noise reduction will?  And as Bert Nase points out, to do that to large volumes of images increases workflow in a program designed to streamline workflow for large volumes of images.
1- One option is to change the process version in your first photo (2003/2010), then copy-paste that develop setting to the rest of your images.  This will get all of your images to the point in your workflow where you can use the Spot Removal Tool on each image.  Once spot removal is done, reconvert each image back to the current process version (2012) then re-accomplish the spots that reconverting lost.
2- Configuring presets is one work-around option, though you will need at least couple of them tailored to your workflow.
3- Changing your import settings to an earlier Process Version is an option, then accomplishing Spot Removal on each photo, then updating the Process Version on one and copy/paste to the rest, then re-accomplishing for each photo the spots lost in the conversion and continuing your workflow from there.
Readers of this thread can use the link above, but it can introduce its own issues, too.  As noted, switching back-and-forth between Process Versions can delete some of your already-corrected spots and you'll have to re-correct them.  Worse, a window prompt asking to create a virtual copy or proof will occasionally begin popping up.. closing the window, clicking "cancel", or choosing any other option in that pop-up window won't be "remembered" and the window pops back up with any further "click" on the image.  Lightroom has to be shut down and the computer restarted for the issue to reset.
Yes, it's very frustrating and time consuming to say the least.  So, unfortunately there is no fix, still only work-arounds.  Hopefully this issue will be addressed and remedied in either the coming release of 5.2 (doubtful) or the Cloud version of Photoshop + Lightroom.