I have had an LP1 which is nearly identical to the LP10 and better than and LP2, ( more adjustable sights) but now shoot an LP400 Carbon. They are not that dissimilar. There is more grip adjustment on the Walther which is good for me as a left handed right eye dominant. However, I find the LP400 a tad light and have added additional weights to compensate for this. Some more mature people or people with a smaller stature prefer lighter pistols, so depending on how you're built this may be a factor. Of course its best to try first if at all possible, but ultimately I bet your averages will climb with either, since you will be getting the chance to practice at home, even if dry firing, and you will get used to YOUR pistol which can be adjusted to yourself. On a final note, it's easier to get spares/repairs for the steyr, but how often do you need spares for these bits of kit!
Hope that helps!
Steyr Evo 10, Anschutz 8001, BSA Scorpion SE, BSA light Pattern, HW77k, HW30s, AA TX200, HW45 Blackstar, HW40, Walther CP88, Webley Premier E, TBC!