Here's a Full Analytical Solution (FAS) for this puzzle, for those who are interested:
The empty puzzle:1) Pre-filled boxes.
2) The 2x in 6h must be [1,2].
3) The 8: in 8b must be [1,8].
4) The 7- in 7f must be [2,9] due to the [1,8] in 8b.
5) The 14+ in 2d must be [6,8] due to the 5 and 9 in row 3.
Through step 5:6) The 38+ in 7a must have two 9s, because it can only have one 8 due to two 8s being spoken for in rows 7-9. (Largest otherwise would be [9,8,7,7,6], which is only 37.)
7) The 10+ in d7 must be [3,7] because of the [6,8] in 2d and the fact that the 9s are now spoken for in rows 7-8.
8) The 38+ in 7a must contain one 8 due to the fact that two of the three 7s in rows 7-9 are now spoken for.
9) The 38+ in 7a has a remaining balance of 12 after the two 9s and 8 have been established. The 9s and 8s are spoken for, and this can't be [6,6] due to the 6 in 7c (the symmetrical [9,6,8,6,9] would force the 8 to 9a and the 6 to 9c). Thus it is [9,9,8,7,5].
Through step 9:10) Multiplying out the 38+ in 6a, the 168x in 8e, and the 180x in 7i, we get (9x9x8x7x5)x168x180 = 685843200. Factoring out the bottom row, we get 685843200/9! = 1890. We know that three of the remaining cells must be [5,7,9] because there are 5s in both the 38+ and the 180x, and 7s in both 38+ and 168x, and a second 9 in the 38+. Factoring these out gives us 1890/(5x7x9)=6. So those 5 cells must contain either [9,7,5,6,1] or [9,7,5,3,2].
11) The 1- in 8g must contain a 4, because it's the only place remining for a 4 in row 8.
12) The 5 leftover cells from step 10 must now be [9,7,5,6,1] because otherwise there's no room for a 6 in row 8.
13) 7i must therefore be a 1, because the 1 in row 8 is already spoken for.
14) This in turn sets the numbers for the 2x in 6h, the 7- in 7f, and the second 9 in the 38+ in 7a.
Through step 14:15) The remaining cells in the 180x in 7i must be [6,5,3,2] because the 1s in columns g-i are all spoken for.
16) The 168x in 8e must therefore be [7,6,4,1].
17) 7b must be either 3 or 5, depending on the outcome of the [3,4,5] in the 1- in 8g.
Through step 17:18) Taking the sum of the 19+ in 1g, the 28+ in 4i, and the 180x in 7i, we get 19+28+17=64. Taking out the whole of column i, we get 64-45=19.
19) The value of 5h must be 5 or higher due to the fact that the largest values for 4-6i is 24 and that the 4 in row 5 is spoken for in 5c.
20) The cells in 9g-h cannot be [3,6] because that would force 1g-h to be [2,3] in order to satisfy the sum of 19 from step 18, keeping in mind the minimum value of 5h from step 19 and the fact that the 1s are spoken for in columns g-h. This would also mean that the 3s were spoken for in columns g-h, which would force 8i to be 6, which would contradict the 6 already used in 9g-h at the start of this step.
21) The cells in 9g-h cannot be [2,6] because that would block the 2s in columns g-h, making it impossible to satisfy the sum of 19 from step 18. (The minimum values are 2+6+5+3+4=20.)
22) The cells in 9g-h cannot be [2,5] because it would be impossible to satisfy the sum of 19 from step 18 without having duplicate 5s in both 5h and 9h.
23) The cells in 9g-h cannot be [2,3] because this would make 8-9i [5,6], which would make the largest value for 4-6i 4+8+9=21, leading to a minimum value of 8 in 5h due to the 7 being blocked by 5g. This makes the sum of 19 from step 18 impossible. (The minimum values are 2+3+8+3+4=20.)
24) Thus, the cells in 9g-h must be [3,5], which means that 9i is 2 and 8i is 6, which in turns leads to more resolution of previous sets.
Through step 24:25) With the 6 in column i spoken for, the minimum value of 5h is now 6 (28-[9,8,5]=6), and the minimum value of 1g-h is still [2,3]. Both are needed to fulfil the sum of 19 from step 18, now that we know that 9g-h are [3,5]. (3+5+6+2+3=19)
26) The 12x in 6f-g must be [3,4] due to the 6 in 6b.
27) The 2- in 3h must be [7,9], which leads to many easy resolutions in sets at 2g, 2d, 4f, 6c, 7a, and 8b.
Through step 27:28) The 5- in 3b must be [2,7].
29) The only place for a 5 in row 5 is 5b.
30) This leads to a 5 in 1c, necessary for the 240x.
31) This last 5 goes in 2f.
32) The only place for a 7 in column f is 1f.
33) This leads to a 7 in 2i.
Through step 33:34) The rest pretty much solves itself.
Final solution:Steps 18-24 were clearly the most difficult part to analyze of the whole puzzle. There were other ways to go at that point, but the ones I saw required too much TAE for my liking. Perhaps clm came up with a more elegant way of getting through that middle section. He mentioned parity in the previous post, and while I toyed with parity during my solve, I ultimately never really used it. So perhaps he was able to see something I missed.
Edit: corrected a glitch in the order of steps 29-30.