i must say, considering the sources, i have no doubts this information is very accurate.
however, i'm taken back quite a bit by it all.
i've lived with several dachshunds and every single one was every bit as sweet as pie. maybe a little high strung (not nippy, but energetic), but tossing a small ball around the house for 20 minutes has always proved sufficient to "wear the stink off" so to say.
personally, i've likened their disposition more to that of a cat than a dog. make them part of the family, give them lots of love, be aware and responsive to their wants and needs... and you'll receive nothing short of unfettered love and devotion. they can be lap dogs at times and want nothing but a warm spot on the couch by your side (or at your feet, in your arms, etc.), but when they want to get down and go they have no reserves about letting you know they want their space. it may seem like they're ignoring you when it comes time for discipline, but simply standing your ground with a disposition that shows your displeasure once or twice always seems to be received. not stupid dogs by any means, but they're not going to stare at you and wait to be shown the right way, typically. they'll learn from their mistakes quickly if you have a little patience and compassion, though.
IME, they tend to pick and choose their owners more than other dogs. the person who shows them more love and compassion, feeds them and lets/takes them out for walks will likely be the first person who's displeasure is received as a warning they've done something wrong and the first person sought out when it's time to cuddle. often the only person for a while until there's been enough times where that person isn't there at the very moment the pup feels it's time for some cuddling.
they really do appreciate an ample yard space for their size to explore and possibly dig up mole tunnels and such. very curious and will follow a scent as far as their physical boundary allows. without a fenced in yard, letting them out could easily lead to a situation paralleled to a senile old man lost in his own mind wandering aimlessly trying to find his way.
one place i lived, we had a doby and a dachshund. the doby was large and a little bit (understatement of the year warning) disturbed. he was purely an attack dog and had no place being in a family environment. one doby that by no means could be even the slightest bit distracted by an entire side of beef let alone a steak. only dog that ever truly scared me, and that's really saying something! however, the tiny, demure dachshund was definitely the alpha, but i've seen that napolean complex in just about every small dog breed i've ever encountered, so no surprise, really.
while i'd say definitely heed the warnings of the other members, i definitely wouldn't let them sway my decision if i truly wanted a dachshund. if you get one with a good disposition, the rewards far outweigh the negatives in my experience. knowing what i know now, i'd just find a breeder and get to know a litter... put a hold on a couple from the litter that seem to have good dispositions and visit them a few times to get to know them so i can make a better informed pick.
a couple things i really like about dachshunds is they're not your typical spiteful, pee on anything all the time, yap, yap, yap, chase your ankles to the door constantly nipping annoying little dogs. that's just my experience, though. i could be completely off the mark and the 4 i've lived with could all have been exceptions to the rules... especially since all their owners were exceptionally loving and patient with them. for what it's worth, they're one of very few small breeds i'll even tolerate let alone have a special place in my heart....