[SP] The Ledge
I recorded my blind playthrough of Part 1, but it took 2:37:59, and that doesn't include the stuff I didn't record because I was having repeated failures. So I just edited the hell out of it to show just the things that worked.
Link: The Ledge, Part 1embedded
I tried zivi7's method for climbing the funnel, but the timing was just too tight for me. The fizzler would come on just as I got above the red field. I felt confident it was the intended solution, and a good part of the two-plus hours was spent attempting that, but I finally had to try something else.
My solution for getting the cube on the 1 dot button was very similar to sicklebrick's, except that I dropped myself and the cube together. I realize now I didn't show how I got the cube into the tower, but it was done by shooting the portal from the 2 dot platform. I pulled off that move while not recording, then went back and did it again. It only took 3 tries. Frankly, I consider that move to be much easier than the similar move required in Chander's Test 1.
I look forward to completing the rest of this map pack. As frustrating as Part 1 was, I had a blast doing it.
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Thanks for having taken the time to play and for the vid.
There is a good reason why the sliding windows allow the cube to be inserted above the funnel, and are 'closed' (the gap is narrower then) later on. I am sure that you'd laugh about how easy it actually is. The only frustrating element might be the fact that it requires to climb up thrice. At least if you don't find an alternative way of doing it.
Hope you'll enjoy the rest of the map as well. Please make sure to play the latest version. Else some stupid mistakes would allow you to skip whole puzzle elements. Thanks!
Addendum: Well, as you might possibly have noticed it, in the meanwhile, has become version 3 
Here's a demo of me doing map 3 (updated version, I believe).
EDIT: And... I'm done. Overall a highly impressive map pack; looks fantastic for one (though I agree with zivi that in a couple of places it was difficult to see which surfaces took portals - for example, in the mini-laser puzzle at the start of chapter 3). There are some good concepts I haven't seen before (I thought the 'intelligent' surfaces in chapter 4 were especially inspired) and I loved the puzzles, particularly chapter 2 and most of chapter 4. Difficulty is nice and high without being too frustrating and I got a real sense of satisfaction from finally finishing it.
A few notes I had:
- The laser cube next to the funnel in chapter 4 doesn't seem to collide with the player at all - I couldn't stand on it or anything. Not sure if that's intentional or not, but it seems a bit weird.
- A personal thing, but I didn't really like the laser puzzle in part 4 at all. It wasn't quite as bad as I feared when I saw all those cubes, but still... not really my bag. It's also very difficult to tell that the pillar with the cube stuck on top of it accepts portals (perhaps it's not supposed to?) and I only discovered so by wildly firing all over the room. I'm not sure if my solution was intended, but in a way I hope it wasn't as it wasn't very satisfying (spoiler, obviously):
http://steamcommunity.com/profiles/76561198002380422/screenshot/595842621606917285
Other than that, though, this was easily one of the most enjoyable mappacks I've ever had the pleasure to play through. Many thanks for uploading, and you get a nice juicy 5 from me!
My maps: Double Bill / Jam / Oval Window / Gymnasium / Gymnasium Part 2 / Minimalism (collection) / Resolution
All feedback welcome!
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Oh dear, you're giving me a hard time. Have just uploaded a new version (sp_the_ledge_v3.rar)...again....
Thank you very much for the dem-file and pointing out the unintended solution. I dearly hope that you guys won't find many more of those exploits.
Ha, looking at that picture I just linked for a second time I'm pretty confident I just did.... 
My maps: Double Bill / Jam / Oval Window / Gymnasium / Gymnasium Part 2 / Minimalism (collection) / Resolution
All feedback welcome!
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Yeah.. After watching a few unintended vids, and the kendoggs vid, my suspicions are confirmed. I don't think I'll be playing this pack... While it is beautifully done, some of the solutions require almost perfect timing to execute. I tried kens solution to just the first dot, and even knowing the solution it took me 6 attempts to get it. Thanks for mapping..your efforts are appreciated, but I'll bow out on this one.
@El Farmarino
Can't confirm that. It behave absolutely normal to me. I can remember that Jose had some problems in the laser puzzle. They weren't solid. I have to ask if he has coped with that problem. I can't remember. Sorry!
No indeed it's not supposed to; it's a leftover from former versions when I used func_noportals instead of the custom non-portalble surfaces. The solution is totally different. There's also no cube stacking or flipping required 
Will fix that ASAP, thank you!
However that part was quite different at the beginning but I had to redisign it due to performance issues.
I'm very glad that you liked it despite all the exploits so far. Thank you so much for having taken the time to play, record, comment and rate!
I can assure you that the intended solution doesn't require that tedious climbing to the uppermost platform. And no perfect timing at all. Read my reply to KennKong if you like.
Things would look different if you'd know the intended solution. Up to you....
It happened to me once, but when I spawned a new cube via the button, that one was solid.
Was it maybe something like this? If so, it's an engine bug and not a map issue 