JWH-018 is a particularly nasty material in my opinion. THe 'Head Stores' here sold it mixed with a herbal mixture, along with andandamide, oleamide and other 'cannibioids'. The products were related to the 'Spice' or 'Smoke' family of products, and the JWH and synthetics were NOT disclosed on the packaging - all that it said was 'herbal smoking mix' with 'INCENSE' written on it, a list of herbs (valerian, passion flower, various mushrooms and wormwood and shit like that) that were supposed to be in it.
It came in bags of one to five grams normally, or ten gram 'tins' depending on brand. Various smoking mixtures would contain different amounts of JWH and such, depending. Normally the more potent were more expensive.
I will give some examples of my experiences of these smoking products, based on when I was smoking them - weight at the time about 55kg (now still under 60kg, skinny as fuck basically). As a 'baseline' I will use a standard 'heavy packed' 'three skin' joint of Cannabis (White Widow) and Amber Leaf Tobacco as the 'base'. (three skinners are two normal sized 'skins' long with one as the 'weld/base' for the non smokers).
Product 1: 'Up In Smoke'. Mild disorientation from one two-skinner (rolled the same way as the normal joints I smoke), nothing special. Far less potent than cannabis, very 'mild buzz'. After an hour or so I experienced slight nausea and a splitting headache, but during the smoke I merely experienced sensory distortion, the 'pins and needles all over' feeling, and bad fucking cottonmouth. The 'peak' was similar to 'coming up' on cannabis. Big disappointment.
Smoke Plus: Equally good as 'average' cannabis, a lot less 'kick' than Widow. Got me pleasantly buzzed for an hour or three (time distortion, I dunno if it is just me who experiences this). Waste of money in my opinion.
Pulse: Oh. My. God. Right-o. First up, three 'tokes' on this and I was blown into the middle of next fucking week, and then about one gram (a full 'gram' baggie) was tipped into a pipe and packed with pipe baccy of unknown composition. Two hits from the pipe and I was on my ass thinking 'FUCK!'. Within minutes observers tell me I was 'whiter than normal', pupils dialated like fucking crazy for a few seconds, and looking around totally disorientated. One more pull from the pipe and I almost collapsed, pupils became pin-points, and I had to be helped to my feet. I passed on the pipe, refused to smoke no more, and walked off on a 1.5km trip to a 'gaming/net cafe' where my friends were, in the throes of HORRIBLE paranoia, almost blinded from the myotic effects, and feeling like a bass drum was thumping in my head. The nausea was something else.
In the cafe I stared blindly at this screed displaying the 'awesome trippy shit' windows media player displays, and I began to feel intense nausea and a sense of 'tripping balls'.
I made my way to the bathroom where I keeled over, retching. Two amtes came in, kept me awake and 'flushed me out' with several litres of water. After much excessive vomiting I was semi coherent and able to think somewhat. I was also at this point awake. I was then carried outside, given a cigarette, and told I was gonna go on a 'magical adventure'. After 4km walking I was more 'alive' and rather enjoying the experience, except the constant nausea.
NEVER again. Since that, I have only 'whitey-ed' twice, both when smoking extremely potent cannabis strains. ('blue cheese' mixed with almost-pure pollen/grinder dust, and some hydro-ed homegrown crazy ass shit). That pulse stuff caused this type of reaction in several others that I know of.
King B: Bleh. Nothing compared to average 'outdoor grown' weed. Nothing special at all. Though, it did give a nice 'lift' and made classes more interesting, however it also caused intense drowsiness

Now for a slightly off-topic report, Valium.
Male, 55-60kg.
Valium (6 pills 'D-10's, three oral three insnufflated)
Unknown quantity of alcohol + 200mL vodka and 1.5L beer.
One 'blunt' (one skinner, all weed)
Lots of tobacco (smoked)
150mg caffiene pills
More caffiene in the form of coffee and energy drinks.
I have been 'off' valium two weeks (As in, have not abused it in two weeks) and I realize now that it is fairly habit forming.
I happened across a LARGE supply of FREE Valium D-10's (apparently the most potent) and after that it cost me a euro a pill. Man, that shit was WHACK.
I was told 'DONT DRINK WHILE TAKING VALIUM!'.
Well, my first time, I had three pints of beer before trying it (to gee me up... or something) and took the two pills orally, washing them down with several shots of Vodka. After ten minutes lag-time I took another sub-lingually, but after two minutes waiting I washed her down with vodka too. Another ten minutes passed, resulting in me crushing three pills into a fine dust, and insnufflating the buggers. Another few shots went down me and I ended up just necking the rest of the bottle (small 200ml 'naggin'.) (shots were 'capfuls' cos I had no damn shot glass).
Walking around, I found myself a nice 'blunt' of cannabis and smoked that up, feeling INTENSELY baked and a bit lethargic. a bit of walking around later I felt more energetic, and proceeded to walk 2km to meet some friends who were also going drinking. After some time we went on a walk, everything looked so 'FRESH' and 'AMAZING'. I made a total ass of myself air guitarring randomly while listening to Nirvana, and we happened across an abandoned bathtub.
I found myself possessed with the idea of stealing this fucking tub. it was my goal. So I coerced mis amigos into assisting me in 'borrowing' it and relocating it by a few miles in the middle of a really dodgey estate. We went shopping and made the purchase of a crate of Miller. Walking back to a friends house, we found a shopping trolley.
Again, I found myself totally possessed. I HAD to get in it and go down the hill. No option.
Well that was a bad idea... I went down the hill, stacked it against a low wall and was projected into a bin. Fuckin GREAT. Got up and carried on, oblivious to the fact I was bleeding from the head.
Got to the house, felt so drowsy I snorted two crushed caffiene pills, and ate one. Drank some amount (unknown) of beer, and we ran out of beer and food after two hours of watching fight club. We went bin driving. After this I keeled over.
*will add more detail later