I think it depends more on the type of rig (using pedals, MFX or just straight into the amplifier) than the short-term or long-term. I've been using an SG-10 for years because it suits my rig a lot better.
If you want an amplifier that you'll be plugging straight into without pedals or multi-effects, the SG-15 would be better because it's got everything in one.
In comparison, the SG-10 is just a simple, 10-watt amplifier that would get you superb cleans and mild distortion tones for its wattage and speaker size. It is more suitable if you will be getting your drive tones and effects from pedals. In other words, it is a good clean amplifier. It can go heavier but frankly its heavier gain tones are terrible. It's cleans are superb though.
Tone Drive cables (also at Standard Value) are superb cables, I've been using them for years too and they're even better than my USA-made Neutrik cables.