I have been thinking of starting to use something like this, but I am still not for sure if it's a good thing or not? What are you expert thoughts?
Personally they offered me daily junk emails with crappy link exchange requests. I mean... Some PR0 website designed by a 5 year old will link back to your from crap.com/links/directory/crap/category/crap.html containing 100 other links (Not even mentioning its the page no one would ever go to anyway) and they will expect you to link back to them. And such requests will keep on coming every day... Absolutely useless from my experience.
I don't find those services to be worthwhile any longer. Many low quality sites and reciprocals aren't really the way to go these days.
With linkmarket depending on your industry/niche there may not be a lot of sites that you can exchange links with. I did find that there are a lot of gambling, and drugs sites requesting links even though it is no way related to yours. Theres a free option so try it out and see if there are related sites.
Reciprocal links are not so efficient these days. If you really want to improve your link popularity without spending money on buying one way links, try using linkvault or receivelinks networks. Check my sig if you want to learn more.
I used linkmetro on one of my sites for 4-5 months. I only exchanged and linked to somewhat related sites, and never a "spam" type site or junk site. My site is now at a PR4, but I no longer use linkmetro.
Personally, I'd never EVER use any crappy link swap network. 99% of all sites that participate in these are real crappy. So obviously this will not benefit your rankings. Warkot