I've been in a similar position, weirdly after I had already installed A9LH on my o3DS. I had recently acquired a n3DS and since it was on 9.9, I decided to do some hax on it. I wanted to do A9LH, due to menuhax + emuNAND being very unstable, but the risk was making me uneasy so I decided to post about it here on GBATemp.
Eventually I bit the bullet and set it up (using Plai's tutorial) and my n3DS was running on A9LH. It was a ride, but it was worth it for the benefits it had.
I will admit though, it's not for people who are really scared of breaking their 3DS even the slightest. When I downgraded to 9.2 from 9.9, I got a black screen error (An error has occurred...) and I was on a partial downgrade. I had to update to 10.7 and then back down, but I actually thought I was a goner. Each time it told me to restart, I was crossing my fingers hoping it'd work. It did, however that nagging fear that I was going to brick my console (even with a tutorial as well-tested as Plai's) took a toll on me.
If you're not experienced in 3DS hacking, don't feel pressured to do it. Only do it if you want reliable ARM9 access and reliable patched NAND booting, and you feel like biting the bullet/you're okay with tampering with the sysNAND. The results are great, if not amazing, but you need to think about whether the work to get there is worth it to you.