Judah wrote
I would second the last statement here.

As would I - emphatically. As a practicing CFII, I will not, as a
rule, accept an instrument student with less than 200 hours.

But having that much VFR experience has been invaluable to me, both in my
ability to enjoy the hood flying experience (rather than getting frustrated
and bored quickly like a friend of mine did when he went straight into IFR
training) and focus on learning the IFR specifics, as opposed to first
having to learn how to control the plane.

That is absolutely dead on. In fact, when I first fly with an
instrument student, I don't even use the hood, do approaches or holds,
or care about IFR charts. All we do is the fundamentals of flight -
climbs and descents, turns and straight flight, and combinations of
the above. Maybe we track a VOR.

I look for the ability to level out and maintain altitude +/-50 ft,
roll out and maintain heading +/- 5 degrees, and hold airspeed +/- 5
kts. That's all - and that's in smooth air. I relax those tolerances
when it's bumpy. Any combination of inside and outside references is
fine. I don't expect the student to be within tolerances 100% of the
time, either, but I expect him not to consistently exceed tolerances,
and to take prompt corrective action when tolerances are exceeded.

A pilot who has been flying regularly (100+ hours a year) for a couple
of years can do this automatically, and it shows. Someone who is
inexperienced or uncurrent struggles with this, and that shows too.
Someone who struggles with basic airplane control using visual
references will struggle more if he has to do it solely on
instruments. He will need hours and hours of basic attitude
instrument flying before we can even think about moving on to holding
and approach procedures. That doesn't do anyone any good.

IFR skills build on VFR skills. IFR is all about going XC when you
can't see out the window. Before you start learning to do that,
become proficient in going XC when you CAN see out the window.

It's not just airplane control, either. It's radio work (primarily
communications with ATC). It's weather knowledge. It's airplane
familiarity. It's understandig of maps and the terrain they depict.
When learning to fly instruments, everything works in favor of the
experienced VFR pilot, and everything works against the guy who
decides to just jump into his instrument rating right after getting
the private. For that reason, I really do not recommend it.

Michael