I fish streamers with it up in Canon City it doesnt seem to bother the streamer at all, I also have added split shot to hit some deep pools and it sinks just the fly and not the "strike indicator" (the leader I was using was 9tf leader) if you want to go deeper then 9 ft and the streamer doesnt sink the "strike indicator" add tippet or more weight, when the fish takes the line I can still see the bright orange under water, so it floats very good. I dont think I've fished anywhere yet where I needed the "strike indicator" to sink cause of the streamer, the Ark in Canon City isnt deep enough for that.
Coming apart... I tried and tried to pull it apart because I was worried about the same thing, I didnt want to hook into a trout of a life time and have the leader pop off and not only lose the fish but my fly and leader. To put the Leader on you have to buy a connector thingie (marketing at its finest) but the connector kit connects 5 leaders, and I havent seen them at a store but maybe you can just buy the connectors and not a kit every 5 since once you have the tool you can use them on all of them. WHo knows. Here is the kit http://www.yagersflies.com/scansyl2llic.html
The way it works is you slide your fishing line into one of those connectors on the kit tie an overhand knot (get it wet, spit, whatever) pull the knot tight and into the connector. Then the connector goes into that tool on the leader comes with one already attached and they pop together, with a little bit of force.
Is it to big to go threw the eye? not at all matter of fact it slides threw the eye better then my knots did more arrow dynamic.
Its not something I think I would have bought without knowing someone who tried it or something like that, mostly for all the reasons you mentioned. But since they gave them to me at the show and I've used it first hand, and the leaders are the same price as the other leaders on the market I think I'll keep using them.
Im one of those lets get out there and do it type fisherman, the sooner I can get my 5 peice Cabela fly rod together and scout an area and start fishing the better. These save time putting them on when I need a new one, plus I dont have to tie in a strike indicator since I have one built in. (I know I'm shaving mins but hey, hehe those are mins I can spend fishin) I am also color blind so I find it hard alot of times using a dry fly as an indicator cause its hard for me to spot the fly. But with this its alot easier to see where my dry fly landed when I am dry fly fishing, helped out tons when I was fishing the Ark below Pueblo about 3 weeks ago.
I'm not the greatest fly fisherman matter of fact this is the first full year I will be fly fishing, I started around August last year and only went about 8 times that year. This year I've hit the Arkansas in Canon City twice fishing streamers and caught 3 browns between 12 and 15 inches both trips (father n law lives in Canon City, so when we visit the inlaws I head to the river =P) and me and my friend went down to the Ark below Pueblo and caught 2 rainbows each, dry flying a hatch that was going on. (dont know the flies good enough to tell you what it was but, the one that hatches and floats to the top and looks like little popcorn all over the water) The rainbows were just slurping them up right along the edges of the current.