For best performance you need Reclock. Also if you want to watch 24 fps  from 25 fps PAL videos.  And you're rigth Reclock can  change the playback speed.

GPU/CPU saturation causing dropped frames is a fact. For that reason, I have to disable Outer Lighting on my laptop screen, and disable madVR's JINC scaling on 1080p TV.

Reclock has to compute extra data, that's a fact. Whether it uses the CPU or GPU, or whether its computation difference can be noticed, is the only thing that is unclear.

Other than that, I think we're done with this thread.

GPU/CPU saturation

What?

Enough to guess! Please read ReClock readme file.

the only purpose to use Reclock is if you really want ZERO dropped frames 
otherwise it's useless

Great, now that makes it clear.

The main reason for dropped frames is because of GPU/CPU saturation.

So in this case, Reclock's extra processing might instead increase dropped frames for some videos.

it allows to sync SVP's output with the real screen refresh rate
e.g. 59.97 from SVP -- to 60.123 screen

the only purpose to use Reclock is if you really want ZERO dropped frames 
otherwise it's useless

Does it clock more precisely with the video card, and displays more exact source frames, instead of displaying calculated frames slightly before and slightly after real frames? Or does it change anything at all?

But I'm pretty sure my 25fps videos are playing slightly faster without Reclock than with it.

If that's the case, how does 25fps gets rendered as 60hz?

Edit: OK, I verified by recording the playback with and without. It's exactly the same.

I'm curious though. How does ReClock solve the problem of displaying 25fps on a 60fps screen, when not using SVP? (ReClock properties actually say display is 59.935 Hz (DDR))

You didn't answer my question.
Please give me a link to explanation of the problem "where 25fps videos played at 60hz play 4% faster". Or tell more details what the problem?

each have a processing cost
You are mistaken. ReClock can do SVP work lighter. For example:
SVP without ReClock: 25 * (12:5) = 60. Only 1 of 5 source frames showed so in 1 second you see 5 source frames and 55 calculated.
SVP with ReClock 4% slowdown: 25 * (5:2) = 62.5 -slowdown-> 60. Only 1 of 2 source frames showed so in 1 second after slowdown you see 12 source frames and 48 calculated.

With ReClock video quality is better because it consists of more source frames and less calculated frames. Moreover SVP needs to calculate less new frames. GPU load is less. Moreover-2 after slowdown you get 24 fps source speed instead of 25 fps. It gives less calculation of motion vectors by 4% every second. CPU load is less by 4%.

In any time you can enable or disable ReClock and allow any speedup or slowdown (up to 10%) to get more video quality (and less CPU & GPU load).

Reclock... also costs on image quality
I can't confirm that. ReClock don't touch video frames. It make changes to audio track only.

So, what is bad with ReClock and 25 fps video?