As someone who did the IR three years ago and has maintained it, can't agree with Helinut. The only benefit is definitely not just flying from one airfield to another with procedural approaches. There are many times when weather at destination is VFR, but en route and/or at departure point is below VFR minimums, especially with the hill ranges in the UK. The ability to fly in IMC well above is safer, more relaxing and often faster, considering time spent slowing and dodging the worst weather when flying VMC. It is also easier to keep legal, avoiding breaches of the 500ft rule. Of course you've got to know you can get down, which means careful met checks, sensible fuel and alternate planning, but only occasionally do I end up having to divert to an airield with an IFR approach procedure.
And then there are other benefits, like being able to benefit from better winds at say 5000 ft, better fuel consumption and speed, smoother flight. Night flying too becomes much safer with an IR. The interest and satisfaction is not to be under-estimated either. Biggest limitation - cold winter days and icing. In UK during Jan & Feb icing level at best leaves narrow slot above MSA and often means no IFR.
Of course you need an IFR acft to benefit from the IR, but I would thoroughly recommend doing it to anyone, though do appreciate that it does escalate the cost of flying substantially, and is often simply not affordable.