RG8 w/ Lundgren M8 vs Ibanez M80M Hi all!

I have an Ibanez RG8 with a Lundgren M8 bridge pickup. I found the DI from Monstrocity by Meshuggah, and the difference compared to my DI is quite noticable -- mainly that my DI sounds much more dull. Would the scale length have anything to do with that? My understanding was that it has to do more with note clarity.

My next question would then be, if I were to get a new guitar, how much of a difference would there be between 28.6" and 29.4"? I'd be looking between a cheaper Agile 28.6" with Fishman Fluences, and the more expensive 29.4" Ibanez M80M with a Lundgren M8.

Thanks!