Today I was asked by a client if he should upgrade his Magento 126.96.36.199 store to the latest Magento Community Edition 188.8.131.52.
As this question arises more than often I would like to emphasize some arguments for doing the upgrade.
Of course this is question cannot be answered in general because it depends on many factors like level of customization, budget, known issues in the workflow, etc.
Security is always a good argument, especially if one has seen the latest severe Magento security issues (e.g. SUPEE-5344). Although there are patches provided even for older versions there are many minor issues which won’t be patched individually. So number one argument is keep up with the latest bugfixes.
2. Make use of latest new features
To be honest most of the time the number of new features in major Magento releases is straightforward and there won’t be a single feature that you really require urgently (besides e.g. things like the RWD theme or configurable swatches). But also extension providers do sometimes make a break in compatibility for older Magento versions which should be considered.
3. Lower effort by making small increments
By upgrading in smaller steps you assure that you always keep up with the latest development and the effort for doing the upgrade will be easily predictable and of much lower cost than one huge upgrade – especially if you have an agency that takes care of your shop.
Although I recommend to always upgrade to one of the latest Magento versions please note that it’s not advisable to upgrade as soon as new major versions are released as the history has shown that the likelyhood of bugfix releases is high and also the extension providers have to be given time to assure their compatibility.