yeah- I did something similar which helped the rattling. Just lined the inside of the mount with some foamy tape.
It reduced, but didn't eliminate the splashing.

for the straw situation- I just put a small piece of duct tape on it, holding the aero fairing to the bottle. works just fine but looks kinda' trashy.

the part that I don't really get is the new, deeper splash guard. you can't just pour water into your bottle with it in there, so come race day, I'm not really sure how to use it.

I'm pretty sure I have a 2nd gen version of the 20oz and have never had splashing or straw issues. Only issue I've had is I have a relatively wide aero bar width that the mount didn't really accommodate and it finally cracked and broke. The PD mount has extensions so I tried that mount with the Torhans 20 and had success.

I don't know how the straw is falling off as others describe, I have to pull pretty hard to remove mine after a ride. Strange...

I've had 1st gen, 2nd gen and 3rd gen bottles. the original straw was clear and not blue- and is of a firmer material. It doesn't come out, but is on the short side.

the newer versions come with a blue straw that is thinner walled or softer material, and slides in and out more easily. The aero fairing comes off the bottle pretty easily over bumps, and then the weight of the dangling fairing will slowly pull the straw right out of the bottle and you don't even notice it. A little piece of tape fixed that problem easily enough tho.

I'm guessing that your wider aero bars, with mount wings fully extended, create a fair amount of shock absorption so that you don't get splashing. My bars require the wings to be flipped fully up or fully down for it to work, so the shock is more directly emparted to the bottle.

roads in my 'hood are brutal as well. I don't have any of these problems on smooth roads.

I have the blue straw and have never had the fairing pop off the nob it snugs down on. I use the cap that came with mine which blocks any splashing. I guess if you don't use the cap it could splash out of the thinner liner cap thingy. Is no one else using the cap? On training rides I rarely refill and for races where I refill I simply pull off the cap, hold in my teeth while refilling with water from aid station, then replace.

Other than not having extenders for the bracket, I've been very happy with mine and I guess fortunate to have had these issues.

I the blue straw version and it did just as morey000 described, the fairing detached from the bottle and it started dragging the straw out. I too used the two layer splash guards. The roads were very rough, but my PD aero bottle with loofa sponge worked better.

Regarding the computer mount, mulling over it last night in my turkey haze, I think I'll defer to the master of fixes and use a small strip of velcro to keep it on in the forward position (thin velcro between the mount arms and bottle groove) .

Also, thinking about the ride, I have an old Garmin Edge 305, (its a mini brick) attached to the computer mount. It was rocking and rolling like van down by the river on a Friday night when doing over the bumps (bouncing like a diving board at a fat camp men's canon ball competition). I think it transmitted a lot of motion to the bottle and maxed it out, resulting in the excess splash and straw mast coming off.

So, with the help of velcro, avoiding the crummy roads, and getting an updated/lighter bike computer, I'll give Torhans another go. I think we can get along. No hard feelings. I want to love you, but the first date just didn't go so well (like the first date with a hotty that she vomits in your BMW, tough to ignore....sometimes you just gotta give it another try).

Anyone have a better fix than duct tape for the straw mast?
Aero for a bottle is cool and all, but when you spend 10 seconds every mile pushing the straw mast back down, I'm sure it is negating any improvement over my old PD Aerodrink.

I used foam pads and it still rattled like crazy. And going to try the velcro, especially over the top part for "softer" rest.