Hi Rav and welcome!!
Couple of points. Firstly (and I am not being picky here, it is for future reference and to prevent confusion!) the correct term is eyepiece. An eyepiece can consist of a number of elements, and those elements can be called a lense. Sometimes if you are referring to an eyepiece and call it a lense, people think you are talking about a camera lense.
Secondly, increasing magnification has a couple of effects. Mainly it also magnifies and atmospheric disturbances.You will probably see this if you switch from the 25mm to the 10mm and is really obvious with planets. If you go to a 6mm, the effect is even more marked. with a smller scope you really need good conditions to get the best out of a high power eyepiece Also a higher power also reduces the Field of View (FOV) so you have to move the scope more to keep the object in view.
My usual recommendation for beginners is to use the eyepieces that came with the scope for a while before spending money. They are usually not too bad and do a good job, especially the 25mm.
The GSO eyepiece you mention would be essentially the same at the SW ones you have, a basic Plossl design, so if wanting to try a higher power one it will give an idea of what they do without forking out to much $$$, but I wouldn't be replacing at this stage.
A Barlow can be a good idea, just be aware that the optical effects of a shorter focal length eyepiece will still be there with a barlow. The only difference is if you barlow a 10mm eyepiece you get efectively the same view as a 5mm one, but with the eye relief of a 10mm. You are probably already noticing that the 10mm has a smaller eye lense ( there's that word again!) and you have to get your eye much closer to it. The effects is even more so with a 5 or 6mm one.
Malcolm