It’s no secret that Firefox has long been my browser of choice due to the ability to customise it to suit my needs. However overdoing it on the add-ons can certainly have a detrimental effect on your browsing experience. Computer World has an unusual article on the top 10 Firefox add-ons to avoid. A follow-up to a more standard top 20, it is the negative list that certainly proves the most interesting, dealing primarily with acting as a good net citizen. Or netizen if you like that hybrid language 2.0 stuff.
In particular it highlights the mixed blessings of FasterFox and AdBlock. Most users will find the former does increase their browsing speed, but many are not aware of how it does so. FasterFox pre-caches all the sites linked to on the current page. Given the number of links on the average page, this can easily mean loading dozens more pages in the background which is a needless waste of bandwidth for both you and the respective hosts. As someone who pays for bandwidth I have no problem with people regularly visiting the site but certainly object to my bandwidth being wasted. For those who insist on using this offender, there is a more responsible “Courteous” setting in the options which offers less of a speed-boost but does so without increasing server loads.
AdBlock is more of a conundrum since I both use it and feel somewhat guilty for so doing. Many sites rely on advertising to fund their own existence and if everyone were to block their ads the site would cease to exist. However no one should have to endure pop-ups or intrusive animated flash ads while surfing either. If you use AdBlock, spend a few minutes visiting all your regular sites and whitelisting them, disabling the add-on for that site. Only re-enable it if you find a site uses particularly intrusive advertising. This way you will not see ads for sites you visit only only once or twice (and where you bandwidth consumption is therefore comparatively low), though you once you find yourself making repeated visits you should enable the ads.