The reason Glenn Cronkhite stopped selling the type of bags with the pouch on the outside of the case was because it put a lot of stress on that compartment nd they would come apart from the case much more easily than the "G" style bags that you have now.
With the single cases, they do take a bit of getting used to. If you are using a gig bag, its probably the best design out there to keep your horn secure, or as secure as they can be in a bag. The design also keeps it balanced within the case so it is easier to carry on your back.
The order that I found works best for the G style cases (bearing in mind I use hard cases now) is:
1) Unzip the case
2) Separate your bell and slide
3) Place slide in the slide holder
4) Remove the slide holder
5) Slip the bell in
6) slip the slide holder in
If you have other things in your case (like the zipper pouch) that makes it slightly harder to handle. I would have liked to attach the pouch to the slide compartment, but like I said, I don't use one anymore.
I was told by Glenn that putting a horn in a bigger gig bag than it should be wasn't recommended. I would assume that means putting a single horn in a double case. Although I had a double case that I really did like.
I think in hindsight, I'd ideally like to have a double G gig bag and a golf club case from SKB for the times when I need to protect it.... but I'm invested at the moment in a few eastman cases for my tenors and a Protec case for my bass.
Hope that helps, the gig bags aren't the best protection, and they aren't even the lightest of cases. But they provide a very convenient way of carrying them around. If you aren't walking around with your case a whole lot, it might behoove you just to try a hard case that has the slide on the top part of the case and the bell on the bottom part. In my case (pun intended), I mostly carry the horn from the a parking lot into a building. Less than 5 minutes anytime I'm carrying it. If i were walking around the NYC metro system, I'd be using a gig bag in a heart beat. As it is, the extra weight and bulkiness of a case is no problem for me.
Someone on the trombone forum asked about slide bow materials, and I answered with some of my personal experience in dealing with this.
I'm a huge fan of the nickel slide crooks. Really feels like it "opens" the horn up to me, by a lot - yet maintains a clarity of accuracy that I couldn't get if I attempted to replicate the feeling with a yellow crook and compensate elsewhere. Really on all bore sizes that I tried. It's what led me to sell my Mt. Vernon 9, I really thought a nickel crook on it would be better but I didn't want to take a torch to something that rare.
To go a bit down the equipment rabbit hole concerning how the slide bow material interacts with other parts of the instrument:
I have to agree that the slide tubes are more pronounced of a change. I also think I have a unique perspective as I've now had 3 slides that had differing slide tubes (yellow upper/nickel lower) and two of them I played them both before and after. However, the two I had done were also converting to dual bore slides, one altering the lower one the upper. In both cases I added a yellow tube to a slide that previously had nickel tubes and a yellow crook.
Both times I did this procedure, it was similar to changing the crook in terms of changing the feel of how it played. It made the sound denser and slightly less articulate than the nickel components, but it brought it into balance with how I like a horn to play. Its a small sample size, but I seem to regard as the three parts of the outer to be roughly equivalent in terms of how it will change the response. E.g. crook = upper outer = lower outer.
If I was still doing music as a main thing, I'd be experimenting with these combinations. Perhaps the best slide I've laid my hands on was a Shires T0825GLW, which had rose tubes and a nickel crook. I sold it a few months ago and it seems to be for resale again, and it's unbelievably tempting to not pick it back up. The only reason I sold it and haven't consequently re-purchased it is that I have more specialized shires stuff now, and the gold tubes give the sound more density than I like for commercial stuff. If I had a job right now, I'd probably pick it back up and swap out the upper tube for my T08LW's upper, which is a yellow tube. But the T08 has a really good commercial sound, and I have a large bore shires (T47LW) of all the 'legit' stuff I do. Even then, I think my ideal slide for that is a T47GLW. But I could see having an upper yellow and lower gold might work too.
In short, when I try this stuff, more copper content seems to add density to sound at the expense of articulation, and nickel the opposite. But balancing out one gold component with a nickel component and a yellow does what Exaclee mentions - dials the horn in. Then there's the leadpipe and how it interacts with all of this. I'm on a sterling pipe for my legit stuff now (Shires 2.5SS! in my T47LW), which I find perfectly draws a balance between articulations and density of sound. If I were to do what I mentioned, I might have to try a different leadpipe that is less dense, etc.
All of that said, I notice the difference more on lighter-weight slides compared to slides with heavier over-sleeves. With over-sleeves, I seem to gravitate towards all nickel. I personally wonder if the material we touch has more of an impact solely on some of our perceptions rather than making a real externally perceivable change. Like the differently weighted valve caps, the copper neck-pipes BAC is making, the thickness of over-sleeves, etc.
Placebo? While it plays a role for certain, I really don't think it's a major part of this. A lot of guys can go in blind folded and tell the difference in these parts. Did that at ATW a few years ago myself and could tell 100% of the time a slide came up with a nickel crook on it.