*shrug*
Here's a shock to those who know me...I'm going to speak against "conventional wisdom" about bipes. *heh* (Although, I'll certainly grant, conventional wisdom is conventional for a reason. ))
First of all...a bipe as a second airplane is, imo absolutely no different from any other second airplane in the sense that IT'S NOT A TRAINER. it will not do things the same way your trainer does, it will do some things better (like rolls for example) and some things worse (like "floating" for example).
Like any other "new" airplane, the best approach, imo, is to spend some time on a sim, ask around, and watch...do what you can to learn what unique characteristics your new plane will have...and then fly within the limitations set by them.
Keep in mind that most of what you're reading above falls in 1 of 2 categories: Either it's conjecture presented as fact (Most pilots find it easier to lose orientation when flying a biplane? Huh? ) or it's someone's opinion of what's normally true, applied to ALL bipes.
The bit about bipes not "floating" well is STRICTLY a function of design and intent. heck no, a Pitts doesn't float well...it's pretty much an overpowered brick. The only reason they HAVE wings is we need something to hang the ailerons off of. of course, it's not SUPPOSED to "float"...who the **** goes to an airshow to watch a guy 'float' by? They're hard-core aerobatic airplanes...and they fly like it.
On the flip side, I'll put a well built Sig Hog Bipe up against any "low wing trainer" you want to name in a timed glide or deadstick glide. Your 4-star will be back at the pits looking for fuel by the time that thing settles down. Remember, the extra wings do indeed add drag, but they lower wing loading too.
Again, it's all about the trades the designers choose to make.
You'll hear people say they DEMAND rudder...can't be flown without it, they'll scream. Bah. While I'm generally of the opinion that ALL planes "need" to be flown with rudder, the mere presence of a extra wing doesn't make that any more or less true. Again...it's about design and intent. I can bank-n-yank the 33% Pitts all day long, and it's quite happy...on the other side of the fence, a Beech Staggerwing might as well not even HAVE ailerons for all the good they do.
The whole point here is this: Biplanes are like anything else in this hobby. Some are designed for a particular purpose, others to be more "general"...each has its own traits and characteristics, some of which may be quite unsutiable for any GIVEN pilot at a particular time, others may not. Is it truth that many biplanes share certain characteristics as a result of their additional wing? Sure. But those traist don't make them "bad second planes"...they just mean they require different skills than a trainer...you know, like any OTHER "second plane" out there.
If ya want a bipe as your second plane, knock yourself out. Ask around, find out which ones are particularly nasty in their "bipey-ness" (Pitts, some ultimates, that sort of thing), find out which ones have certain "bad" characteristics (Wacos tend to build heavy in inexperienced hands, Stearmans are frequently underpowered, etc), and find out which ones have characteristics traditionally considered to be more friendly (the Hog Bipe, for example).
heck...go out to the field and ask someone to buddy box you on a bipe...talk to them...sim some.
Don't just write them off because they don't fit in somebody's "plan" for progression. Just be aware they have their own personalities, and do the work necessary to decide if you want to tackle them, and if so, how to do it.
/I'm a bipe flyer and I approve this message.