I think there are basically 2 criteria for selecting a multi-tool. The first is the "cool factor". MTs are slick and offer all sorts of things to geek out about: the best combination of tools, best steel, plier strength, fit and finish and on and on and on. This is perfectly valid, or at least, just as valid a geeking about the similar issues on regular knives. I mean this sincerely, if this is the direction of your heart, buy the coolest MT to your eye and carry it along side of a cool knife and carry them both because they're cool and it's enjoyable to have them with you. In the grand scheme of things in this life, carrying an MT because it makes you happy is just fine.
The other reason to carry an MT is straight up utility where utility is defined by the jobs you encounter, your carry preference and the tools on and the size/design of the MT.
In reality, I wager that most of carry an MT for some combination of these 2 core reasons.
I'll try to come at it more functionally. Like you and many others here, I prefer pretty much everything about carrying a dedicated pocket knife. I've come to view a knife blade on an MT as being, as my great-grandfather said, as useful as a capon in the hen house. For the most part, I don't use the knife blade. There are, for me, 2 exceptions.
First, for EDC, I carry a knife in the RFP and a Micra in my LFP with a full size Blast riding in my day pack. The blade on the Blast never ever gets used but the small pen blade on the Micra is useful for some cutting tasks that are better with a small blade than with a full sized blade. This is one reason why I think Leatherman did the right thing by downsizing the blades on their Juice line. When I look at small pocket sized MTs, I see them primarily as a backup/companion to my EDC knife and in that usage, having a smaller blade compliments the larger blade of my EDC knife.
The other time I like to have a knife blade on my MT is when using the MT in a shop setting where I'm doing things that I don't want to use my EDC knife blade for like scraping battery terminals, cutting fuel lines and opening pesticide bags. I treat my EDC knife as something as a clean blade and use the MT blade as a dirty blade - but then, I use my EDC knife for eating. Anyway, for this type of stuff, an MT with an external blade like the Wave which sits on my work bench makes sense to me.
The last thing to consider is carry style. I hate holster carry which for me, limits my carry of full sized MTs to either in my pack or in my back pocket. For EDC, I prefer something small. The Micra is just fine. Others might prefer something like the Juice
Given my sage 1 has s30v I was thinking of just carrying that with a lesser bladed multitool (420HC or something soft like that). I could just save up though for a Charge TTi and have a multitool with s30v...but I would be down an additional 100 bucks
