Most definitely worth it! I've replaced the cutters on my wave plus once and had resharpened the originals a couple times. I beat on that thing like it owed me money for 6 years and it was still in pretty good shape. I didn't even know you could still get the original wave. Also the plus with the replaceable cutters just cuts better to start with.
Now all that said, the wave scissors suck, the eyeglass drivers worthless IMO and alot of times i really wished it was bigger.
I just got a surge a few months ago and it is amazing. I drop it in my pocket and forget its there, but when I pull it out it's a much more usable sturdy tool. My wave now feels dainty when I pick it up. I have not went back to my wave. I would highly encourage getting a surge. Or if your really wanting the size of the wave, do you also carry a good knife? Or is your multitool your knife? If that's the case its Definitely worth upgrading to the charge tti for the same tool with the s30v blade.