I am very interested in the subject of flickerfixers because I have been coding interlaced Amiga games and business software since 1985.
Just to be clear: I have seen many screenshots of GBS in action.
GBS video is never ever "clear".
It changes the colors around.
It changes the pixels around.
The way it samples the incoming video signal is a bit off so it always adds distortion.
It also draws waaaaaaaaaaaaaaay to much power from your RGB port. Over 10x more than is legal. You are liable to destroy your RGB port after a few years of this sort of abuse unless you wire up an external powersupply.
GBS force converts all 50hz PAL modes into 60hz which messes things up as its impossible to smoothly upscale 50hz to 60hz.
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You had a problem. Your problem was the monitor manufacturer ripped you off with a monitor that could display 50hz pictures just fine but was rigged (sabotaged/vandalized) not to display 50hz video on purpose. :destroy: This way they were knowingly selling you an obsolete product which you would then immediately need to buy a replacement for. :flame: This doubles the profits of the monitor industry.
The solution was to buy a proper monitor.
But instead you made your problem worse by adding a GBS which damages the video quality of every single Amiga gfx mode, even the ones that display on your silly obsolete monitor that they tricked you into buying.
So now you have 2 problems instead of just 1.
You can reduce your problems down to 0 by buying a normal (not ripoff) monitor from a normal (not ripoff) monitor manufacturer + a good flickerfixer.
I am not even sure u need a flickerfixer. If you want to play PAL games the best way to do that is to simply play them on a 1084S. It gives the absolute best picture quality for lores PAL games.
You only need a flickerfixer for Amiga gaming if you are going to play interlaced Amiga games such as Total Chaos AGA, which runs in HIRES PAL LACE (640x512x256). The game does not flicker much at all (some ppl don't even realize it is in interlace) when playing the game in the normal way. But if you turn on the Dungeonwars option then certain dungeons use walls that have perfectly straight horizontal high contrast flickery lines. But if you get lucky and the dungeon is constructed of trees or giant snowballs or what have you, then you should not have a flicker problem. Most of the game was created with antiflicker magic technology but after a while I got sick of doing that and said "let them buy flickerfixers" 
If you decide that you will be playing interlaced games such as Mechforce ECS, TotalChaosAGA, Roboforce, SimCity 2000, A-Train, etc. etc. then you should get a good flickerfixer and a good monitor that is not racist against various Amiga gfx modes. I am currently using a ViewSonic UltraBrite A90f+ multisync monitor that works with NTSC/PAL/etc. etc. Amiga gfx modes perfectly with my superduper internal flickerfixer. There are many other monitors that work perfectly with flickerfixed PAL/NTSC/VGA/etc. such as Commodore 1950 Multisync, Commodore 1960 Mutisync, NEC Multisync 75 and many others.
Internal flickerfixers always provide a superior picture to external ones, assuming no bugs or manufacturing defects.
Internal flickerfixers do not have to digitize the incoming video signal. They actually use the REAL digital original unmodified video signal and they have perfect timing information from the Amiga gfx chips. So internal flickerfixers provide the correct colors and the correct pixels. Its beautiful. :knuddel:
All the internal flickerfixers I ever used or read about all allow switching video modes instantly and properly without having to press any manual buttons.
External flickerfixers do not have perfect timing information. They simply have some dumb pixel clock rate that they digitize the incoming signal at. Since it is not the correct rate, some columns of pixels do not digitize correctly and you get a smeary image.
GBS was really made for old Nintendo and Sega consoles. That target market does not care about quality. (If they did care about quality then they would be using Amigas) 
I have an Indy ECS, and several GBS 8200s, and use VGA monitors on all of my Amigas. For $30, IMHO, the GBS is hard to beat. It looks just as good on my LCD and CRT monitors as the Indy ECS. The only thing I have seen is a little distortion around a moving mouse. Other than that, I've played games that look fine, but I am not a big gamer.