So many things to consider here. Both Rebar, Spirit, Wave have excellent saws, very capable and much better than Gerber's or SOGs.
If you want nice Phillips and flathead, I just can't recommend getting a SOG. Their Phillips are infamous because they don't seem to fit any screw size well, and most people have all kinds of trouble with the Phillips drivers and the (soft, badly shaped and weak) flatheads.
In fact, many of us take them out or swap them by the excellent Leatherman Long Phillips (like I did on my SOG Powerlock below)
The Rebar has this big nice Phillips driver as well, similar to the Spirit Phillips driver. The Wave has both flathead and Phillips in the form of one double sided bit for the bit driver. Occupies less space, but can't handle much torque or reach recessed screws, a big disadvantage IMO) but has many shortcomings and you can lose the bit.
The Wave is also heavier, has worse ergos than those two (many people can't stand the Wave's sharp edges and corners) but can be carried via pocket clip. DOesn't have replaceable wire cutters like the Rebar does.
IMO, all can be summed up in:
Wave -
+ Has nice scissors, best file (diamond), swappable bits, OHO Blade, Clip
- Heaviest of the three, short reach and strength drivers, non-repl. wire cutters
Spirit -
+ Most complete & diverse toolset, perfect ergos, super stainless, outside accessible tools
- No clip, standard pen/butter blade, not-needlenose, warranty if outside the US
Rebar -
+ Beastly built, replaceable cutters, sturdy drivers and tools, slim and light, price
- Not outside opening tools, no scissors, locks are slow and basic
So, to me, the best options for a "one forever tool" or your first experience in the multitool world, I'd pick a Spirit or a Rebar and not look back!