Gelspun or Monofilament
The family of lines known as gelspun lines includes two types, braided and fused. Both of these varieties of gelspun have similar characteristics but are constructed differently. The main two advantages of gelspun are a fine line diameter and are very close to zero stretch.
These are made from two types of futuristic fibres which are dyneema and spectra. So at the end of the day most braids are very similar and are probably made out of the same factory. Braided lines normally don't have an outer coating this is what makes the line limper and normally a bit finer than the fused variety. Braids biggest benefits are low stretch, (which allows you to detect bites in deep water) and low diameter. (Which helps you to cast lighter weights more easily and creates less water drag on your line?)
For example using lighter sinkers or trolling your lure a bit deeper. This all sounds great but it also has a few down falls as well, such as the price. It is normally around five times the price of a medium monofilament line. Braid is a lot harder on all your gear such as, rod guides and line rollers. People tend to fish a heavier line class on rods and reels which are not designed for this purpose. Some anglers also fish their drags a bit heavier which creates more wear and tear on gear. Another down fall with braid line is that you cannot tie conventional fishing knots. You basically have to start from scratch. It is also hard to detect line damage with braid and it often breaks without warning. It also tangles a lot easier than mono because of its limpness and super fine diameter. When it does tangle most of the time you may as well get out your scissors and start cutting. Probably the most concerning thing with braid because of the zero stretch. The fish that you lightly hook are normally the fish that you blow. If your drag on your reel has the slightest bump this will be magnified dramatically. My advice to you would be to use it if you really need it.
These are far more user friendly than braid. They are made from dyneema or spectra. But fused line has an outer coating which holds the parallel fibres together, not like braids woven fibres. The coating makes the line a little bit stiffer and handles a bit like mono. It is still has zero stretch and quite a fine diameter but you still require to learn a couple of new knots. One thing to remember with most gelspuns is the labeling of the breaking strain is not correct. For example Berkley fire line 14lb actually breaks at around 20lb. It is nearly twice the breaking strain that is stated on the box. So once again just because Berkley fire line 14lb has a 6lb diameter, which is equivalent in mono doesn't mean that you would spool it up on a trout outfit. In actual fact you are using a 28lb line on an outfit that is probably designed for the use of no more than 10lb breaking strain. So it is a good idea to find out the actual breaking strain before you purchase it.
In my opinion I think that mono is a far more user friendly line. It is low cost, you can run it right to your hooks if you wish because of its transparency, You will lose less fish due to its cushioning effect for hard running fish with hard mouths. It is very easy to tie simple knots with and it is not hard on your gear. If you get a tangle or a back lash and you can't undo it is not the end of the world.
KNOTS IN GELSPUN
The knots that I use for gelspun are not the simplest but are the best especially when using heavier lines.
Bimini twist double connected to braid leader knot.
This is by far the strongest connection to join monofilament to gelspun line. It takes a bit of practice to tie but it is worth the effort. The instructions for this knot can be found in Geoff Wilson's book on Knots and Rigs or you can call in to Charltons Fishing for a free demo.
Braid ring knot.
This is the knot that I use to connect an eye of a hook or swivel straight to gelspun line. It is reasonably simple to tie and also can be found in Geoff Wilson's book on Knots and Rigs.
Gelspun lines definitely have a place in today's fishing but are knot always suitable for every application.