I'm not a big fan of any of those fixed angle sharpening systems. The Lansky gives you a few options, I think it has 4 different angles, it will work like a charm if the manufacturer happened to use one of those angles, otherwise you'll need to grind off quite a bit of metal to reprofile the edge to one of the Lansky angles.
Another shortcoming the Lansky suffers is that it works well with medium sizes blades with somewhat traditional profiles. A recurve blade, like the one on the Spartan, might not be that easy to work on with the Lansky.
I own a Lansky sharpener, I own (or have owned) one of almost any sharpening system out there, and I don't use it anymore. The only times I get it out is when I've got a blade that needs some serious grinding, not sharpening, something that just needs a new edge bevel.
There's nothing as good as freehand sharpening. Once you learn that, you won't need any gimmicks to get your knives sharp, and you can invest all your money in quality stones and more knives. It can be a frustrating learning process, but it's worth it. Especially if you use your knives outdoors, I know I wouldn't want to haul around a Lansky in my backpack.
Practice on some cheap kitchen knives until you get better, try some Spyderco ceramic stones, they rock. You can get them in different shapes, which makes sharpening serrations, recurves, hawkbills, etc. really easy. I like them better than diamond sharpeners because they come in finer grits and leave a nicer finish, I prefer my edges mirror polished. But DMT diamond hones and stones are a good choice, too (the coarse and extra coarse ones are great for seriously damaged edges, or tools that need reprofiling). There are better, more expensive, options than the Spyderco and DMT sharpeners, but they are really good, will last you a few lifetimes, and won't break the bank.
If you must have a sharpening jig of some sort, check out the Edge Pro system. It's not limitted to a handfull of angles, the stones are excellent, the company's customer service is fantastic as well. You can see it here:
Edge Pro, Inc. It probably is the best sharpening system out there. You'll notice it's quite a bit pricier than the Lansky, but it's just that much better.
Spyderco's Triangle Sharpmaker is also good, the stones it comes with are rather nice, it has a fixed angle, but it isn't hard to make it work with just about any knife. Comes with a decent instruction DVD, too.
I don't mean to say that the Lansky is a bad product, it just has some serious limitations. It fits most common knives, but if you happen to own a knife that's smaller or bigger than average or has a less than orthodox blade shape (try sharpening a Spyderco Cricket on one of this things! or a 18" khukuri!) it can be a pain in the butt to get it to work. The same goes for the edge angles.
If you learn to sharpen your knives freehand, you won't suffer any of those limitations. Remember: the more you know, the less gadgets you need!
Thoughts on the Lansky Knife Sharpener
Freehand sharpening is the only way to go on my knives and you really get to know each ones personalities and curves from the effort and intimate time you spend with each. 
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