I've never had an extreme habit, but I have used hundreds of grams in my life - my peak usage was probably 5-10 grams every week or every other week for a couple of months at a time - this was over 5 years ago now. I've also never had very extreme bladder symptoms, pissing blood or extreme pain, for example, but I have noticed a gradual, gradual increase in more minor bladder symptoms, which require less and less use to come on. There is, seemingly, a huge range of variation in how susceptible people are to the bladder effects - if you have a read over this thread from the beginning you'll see a lot of discussion about it. I'd put my own experience somewhat middle of the road in terms of severity, definitely I've been lucky in my experience compared to some - but my lifetime usage is relatively minor compared to others who have never had symptoms. Best policy is just to be careful, keep your usage to a minimum, and make sure to follow all the HR advice given in this thread (in a nutshell - always stay hydrated, take an ECGC supplement, probably spit out the drip, and make sure all other bases are covered as far as your general health, diet, frequency of exercise, etc, etc).
But primarily just keep your use to a minimum, a few grams a month is probably OK, again as long as you follow the previously given advice, just don't abuse it, because once you start to get bladder symptoms you are likely always going to be at a greater risk of getting them again. Treat the drug with respect and look after your body.
Besides that I agree the K comedown is nothing compared to a proper stimulant comedown, but it's still not nothing. Dose matters of course, but even in my very early days, the K honeymoon, so to speak, I remember feeling pretty shitty the first few days of the week after a weekend binge. IMO it's redosing that does it, a single heavy dose resulting in a K-hole, then abstinence, in a K-naive user is probably not going to have too bad aftereffects, maybe even positive effects, people do talk about an afterglow and obviously ketamine has documented antidepressant effects in some cases, but prolonged sessions with multiple heavy doses IMO and also in my experience just scrambles one's brain, ketamine has always been pretty solidly pro-depressant rather than anti-depressant for me, despite my undeniable love for it.