First chairs in the park

you have over 5000 posts, for some reason i think you should already have seen the answer in here.
yes, they will work very well, assuming they fit your foot. they are a boot, you can ski park in any standard alpine boot. also, they are no different than other full tilt boots. (ignoring graphics) i believe the only differnce between them and the seth is a different flex tongue, and them and the twall is they have a rigid boot board instead of an active boot board, and possibly a stiffer flex (twall is 6, first chairs might be 8 but im not 100%)

i just checked and before i get called out, my information regarding the flexes and bootboards was a bit off, but my point remains the same.

first chairs have rigid and 10 flex
seths have active and 8 flex (different from the past i think)
twalls have active and 6 flex

I rock first chairs. I'm 5'10" 185. If you like a stiff boot, they'll be great everywhere. I'm terrible at park but they are my boots... so I wear them when I do park. They are stiff, but I like that. For out of the park, the boot is money. If you can ski a stiff boot they'll be great, assuming they fit you.

They are not forgiving. The only time I get them past normal skiing flex is when I slam into something unexpectedly(bumps, crud patch, too steep of a side booter) going mach chicken, or taking something deep. They rock.

a full tilt flex 10 isnt really stiff at all. like 120-130 max

did not really read op. Just pointing that out.

confused how you think that "120-130" isn't stiff at all considering that a 130 is the stiffest boot i have ever seen or heard of, granted the 3 piece design makes them flex a little softer, but i dont understand how the stiffest boots on the market arent stiff..

  I used to race as a kid and used 150 flex Langes no problem.  I just got First Chairs this year and like them a lot.  Im going to use them for park.  I weigh like 205 6'2 and they are a tiny bit too stiff for park. I may try to find a flex #8 tongue to swap out.  I would get them if you are a bigger guy like me they work fine in park

its no way a 130.

and 150 is the stiffest. 130s is pretty perfect if you ask me.