magisana, The fact of the matter is that very few or any of these 'guru' web sites are worth the money - or even worth any money. Furthermore it is up to you to set up some criteria for evaluating them. There is plenty of advice available on how to do that but we could mention
1. Audited profitable trade records,
2. Are the methods articulated, do I understand them and do they make any sense?
3. If the methods are articulated, can I test them independently.
Questions like is "Fred McGoogly any good?" are not worth asking. Ultimately I fail to see how anybody can stake significant amounts of money on methods they do not understand, haven't extensively tested themself and based solely on testimonials on anonymous Internet message boards.
PS the name "Slice Methodology" would put me off right away.