I've been contemplating a new rod for kayak fishing (as if I really need another rod!). I'm looking at two MHX Spin Jig blanks.

The SJ833-MHX and SJ843. I currently have a 6'8" St Croix Ex-Fast rod, but am looking for a fast action to add to my kayak arsenal.

Am I splitting hairs in this comparison? 

 

SJ843...7', 8-15 LB rated, fast action, med power.

 

SJ833-MHX...6'11", 8-12 LB rated, fast action, med power.

Lure rating is more important for your application, medium doesn't mean anything.

Yeah, I  hear ya! I realized I  had forgotten to add the lure weight ratings.

I have a rod built on the 843 and love it. You are correct, though, there isn't a whole lot of difference between the two. Whichever you decide on, play around a little with placement of the reel seat. I mounted mine about an inch forward of where I did on an L843 made a world of difference balance wise.

My intention is to build a compliment rod to a rod I built on a St. Croix 6'8" ex-fast SCIII blank.

Well, I opted for the SJ833...and I could not be any happier with my decision! This blank has a bit more action in the tip than does the SJ843, but a very similar power rating in the midsection and butt. Patting myself on the back!

You mentioned that you fish from a yak.  For some, that extra 3-4in. in length over the St.Croix Poses a problem. You can, if you like, cut the rod shorter from the butt without affecting the action. I’ve don this on a couple of rods bolt for youngsters. 

My bigger issue was the longer rear grip section of some of my current rods. I find with this new MHX rod, with a slightly shorter rear handle, works perfectly fine. I find shorter rods reduce casting distance, I fish a very clear 100 acre lake 4 minutes from my house, and the extra casting distance is a plus.