Rock Shox revelations vs my current OEM fox

Yes, yes and yes Blootmeister

I've got a 2012 Rev 150 on my 5.7C and it's an excellent fork. Granted mine is the dual-air (fiddly to setup, but awesome once done), tapered and with a carbon crown/steerer (so a bit stiffer), but I think you'll definitely notice the difference.

For one, you'll actually enjoy the exclusive ability to use all of your travel! For two, my preference is for RS damping over (most) Fox options. For three, they're much easier to service and maintain yourself! For four, $400 sounds like a pretty good price!

Now, to add to all of that, I reckon if you combine it with the following link, your bike will feel like a totally different beast!! Granted, the 2 deg cups will add a small amount of stack height, but not so much that you'll notice. The 1.5 deg cup won't suffer from that problem

http://www.workscomponents.co.uk/15-degree-ec44-... or http://www.workscomponents.co.uk/20-degree-ec44-...

In Short - DO IT

So... I'll attack it in two parts

Steerer length:
You'll need to make sure that you've got enough exposed steerer sticking out of your frame to safely clamp your stem with the new fork. I gather that the only spacers in your current setup are below the stem? Or do you have a couple above as well? And is the first spacer one of those conical ones? Sometimes these get confused and can be replaced with cylindrical ones.

If you're only working with a 195mm steerer on the new fork and in theory need 200mm as a minimum at the moment, you'll be in danger of not having enough to clamp your stem onto safely. Depending on your stem, you may be able to change it out to a lower stack-height stem, which may give you that extra couple of mm you'll be chasing. Measure your stem clamp height and see how tall it is. I've managed to find 38mm for my bikes (I've got one spare depending on what stem length you need), but you may be able to find lower still.

Now, by dropping your stem height by 20mm, you'll be affecting the way you interact with the bike. In theory you'll get a more aggressive position, increased steering response, more grip on the front wheel and a better climbing position. Will your body and back like the change? That's not for me to say, unfortunately. You can compensate with higher rise bars, but you're now potentially looking at a bar and stem change!

Angled Headset (linked parts):
What these will do it allow you to run your bike slacker, which will increase stability at speed, in the rough stuff and when descending. The drawback is that you'll potentially give up some climbing ability, although I've completely gotten used to my slack (67-ish) Mach 5.7C compared to my old, steep (70-ish) Mach 4. For the type of riding you and I do, a little slacker will give you more confidence

Now, the problem is that both of the linked parts are going to eat up steerer length, which is something you won't have any of spare with the new fork, by the sounds of it (the 1.5 deg cup will add height above your head-tube, the 2 deg will add height above and below). Each of the external cups is about 7mm from memory (I had a 1.5 on my Mach 4), which is going to mean you're now approaching non-usable steerer length.

Phwoar, confused yet buddy?

OK so, in theory, you could drop the 30mm completely and run the stem as the first "spacer". At 220mm - 30mm that give you a theoretical minimum of 190mm, so the fork will be able to work OK (as long as I'm picturing your setup correctly).

Now, that said, the question is whether you're comfortable riding your bike with the bars in that position.

The angled headsets are probably still out of the equation though.

Can you send me a close-up picture of your current arrangement (Stem, spacers and top of the head-tube)? That will let me totally confirm that you're a) good for the new fork and b) I want to confirm whether you can do a quick change to test out the slammed position. I'll PM you my email addy mate

What's a service on he fox -$180 say?

So for $220 you can get a new fork that s extremely well regarded and you can service it yourself to boot- don't think, act!