I cant speak for others but i can speak for myself.
In my time, i've tried bowling a bit of everything (though i used to bowl primarily seam).
Now, i cant bowl some exotic deliveries like the doosra or the wrong un, reverse swing etc etc. But bowling off spin was heck of a lot easier than bowling leg spin. When bowling off-breaks, i found that it was a lot easier to get consistent with it (ie, line and length) but spinning the ball a lot is a challenge (there was some spin but not boatloads of it).
Legspin i found precisely the opposite - its a lot easier to get considerable spin and extremely hard to control accuracy.
While bowling pace, i found that bowling bouncers was very hard because though i could crank it fairly fast, i cant get much bounce (maybe because i am around 170cm).
Pace bowling is a lot more dependent on freshness factor too - while tired, as a spinner i could bowl a couple of overs that arnt much shabbier than when i am fresh but as a pacer, when i got tired, everything went to pieces- not only pace but also control.
Bowling technique, i found, was far more important while bowling pace than spin ( it hardly ever mattered if i came a bit more chest on or side on as a spinner but as a pacer everything, including how much i jumped and how big a stride i took mattered).
Overall, at club levels, its easier to be a pacer than a spinner, simply because pace intimidates a lot of people and even a little bit of seam movement and decent line is good enough to bag most ( the occasional really fast one peppered in to keep em off guard). Bowling spin is a lot harder because you gotto be very accurate- for while the pace or bounce of a speedster might cover up a bad delivery at lower level, even a club batsman is good enough to club a six off a long hop, doesnt matter if your name is Warney.
Thats my two cents.