Depending on what you buy and what you want to achieve with it, the Shapton Glass Stones are great. They are mist-and-go, cut reasonably quickly, and are capable of cutting and refining very thin angles on both soft and hard steels. They are precise, almost to a fault -- they will cut the angle pretty much exactly as you ask them to, even if it is the "wrong" angle. I like my 500, 2k, 6k Glass Stone progression very much and it has served me well at home including old Sabatier, German stainless, stamped Forschner/Victorinox blades, classic Japanese carbon, VG-10, and Cowry-X.
The more I sharpen different knives with different steels and constructions, the more I come to the conclusion that there is no "perfect" stone or set of stones. I'm tending to like the subtle difference in edge character that a "natural" Meara gives me -- a little rough and toothy so it slices amazingly easily -- compared to the "exactly all the same grit size" of something like the Glass Stone and most other synthetics. Some stones give your knife a "misty" look to the edge, some (like the Glass Stones) can give it a mirror-like polish, even at moderate grit sizes (5 or 6k, for example). Some stones wear down or "dish" quickly, others are hard to even notice that they are wearing at all in home use.
For me? This week? I'm feeling lazy and liking:
- Atoma 140 -- only if knife needs major reshaping
- Nubatama Bamboo 150 -- if I need to thin the knife
- Nubatama Ume 1000 ("Speckled, Medium")
But wait -- If I want something even more screamingly sharp, I'll follow with a Yaginoshima. Feeling less lazy and I'll put a Tajima in before the Meara. Wanting a shiny edge and I'll go 500, 2k, 6k Shapton Glass Stone instead.
Oh, don't forget about stropping -- there are CBN and diamond compounds, and nano-cloth and kangaroo leather, and,...
Good news? Get a decent stone in the 2-6k range and you're already ahead of the game. You can use your existing stones to get to the 1-2k level and finish on your new stone. Once you have one, decide what you do and don't like about it, or what you want different in your finished edge, and you can add another.
Other good news? As much as I love my Konosuke knives, one of my favorites is still a $30-class kurouchi-over-who-knows-what santoku. There are lots of affordable knives here that can get screamingly sharp and hold an edge plenty well enough for several weeks of home use. I've got a Murata funayuki coming tomorrow for under $100, there are others in the same class that have gotten good reviews from experienced knife people and professional cooks here on the site. I also know I don't feel too badly when I muck up sharpening a sub-$100 knife, compared to something a step or two up in price.