I cannot offer scientific proven research.
But I can offer my own personal experience with Spiders and their combos, as well as my thoughts on the whole thing.
I've had Ball Pythons for around 18 years now. That is nothing compared to some other owners, but it does mean that I've had my fair share of experience. I used to do "rescue" and had quite a few snakes that needed care. Some were worse then others, but they all shared one common factor. When stressed, they wouldn't eat. When sick, they wouldn't eat. Parasites..no eating. I also know that pain and "feeling ill" causes a body stress.
That said, from my own experience as well as a few other peoples, it seems that spider and their combos are overall (of course there are always exceptions) very easy to take care of snakes. As long as the husbandry is correct, they are eager feeders and seem somewhat less shy. Even my hatchlings that display the spider gene are the ones that ate first, ate most, were the easiest to switch to f/t rats and seem remarkably un-afraid. If anything, quite curious. No aggression or defensiveness either.
Could all that be a fluke? I suppose so. My adult female never displayed any discernible wobble, other then missing the rodent during a feeding strike here and there. One hatchling seems to weave a bit more then others, also the one that was first to eat.
Going by my own experience I do not feel that these snakes are in any kind of distress. Over time you do get a "feel" for these snakes and their body language. And Ball Pythons usually stop eating if something bothers them enough.
Spiders and their combos can make wonderful pet snakes. But I also understand if some people want to steer clear. Its a personal choice to make.
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