I just picked up my Ping G25 iron set and got pseudo fitted. I went with an CFS-R shaft, black dot lie, and off the rack at the end of the day. I'm lucky to be average height, at 5'10", and have always felt that anything off the rack feels great and comfortable to hit. I have never been fitted my entire life and my G25 purchase was the first.
I have played since I was 14, competitively in high school, but played on and off since college. Interest level, life and work got too busy and I'd be lucky to get 2-3 rounds of golf in a year. I'm now 37 years old, still in good shape, and my interest in golf is renewed. I was thoroughly embarrassed a month ago when I played for the first time in over 2 years. I lost 8 balls and shot over 100 and basically stopped counting. It was a Johnny Miller course, something no one should play on their first outing in 2+ years, but I basically lost my swing. I was playing with a set of forged Mizuno MX-23, which are considered GI irons, but with my lack of play, they weren't forgiving enough. So the first thing I did to correct this was to sign-up for a series of lessons. I've always had a good looking swing to the naked eye, but to the professional instructor, there were plenty wrong. The facility had cameras that analyzed my swing with data and in slow motion, he was able to point out my problems. He had two simple fixes. First was to adjust my grip, and second is to focus on my swing plane. Once I got those two corrected, I am now more consistent and hitting the ball straighter than ever. With my renewed confidence and performance at the driving range I decided that I should refresh my 5 year old set with something new before heading back out to the course.
So now back on topic around fitting. I went to my local golf shop and had a few irons in mind after reading reviews online. I hit a few of each with a 7 iron and liked the sound and feel of the G25's the most. It felt the most forgiving and trackman indicated the highest consistency amongst all the clubs I tried. Now comes the fitting. Lie angle, length, and grip size was a non-issue. I'm average height with a text book swing, just need to work on impact consistency with practice. So next was swing speed. I was clocked at 93mph with a 7 iron and a distance of 170.2 yards with a +.46 launch direction, so pretty much crushed it dead center. This is on the G25 with CFS-R (regular) flex. I told the fitter, I like it, and he tells me that I should use a stiff flex at that swing speed and distance. So I tried the stiff shaft instead. It felt a little heavier, my swing speed came down a little, and couldn't get the same results without working harder. It felt like I had to work a tad harder but the launch angle was slightly lower by about 1 degree, which is nice. I went back and forth hitting R vs. S and the regular flex felt way better for me. What I realized is that my
tempo
is more important than my swing speed. I wasn't torquing my club enough for the shaft flex to matter so much. The slightly lighter shaft gave me higher swing speed and a slightly higher launch angle which I don't mind so much. The fitter didn't even tell me this and I simply recalled a discussion I had with my instructor. I basically ignored the fitter, who was leaning me towards stiff, and went with the club that felt better. Luckily, they had one R flex in stock left for me to take home.
The next day, I went out on the course with friends and shot a 79, only my second time out in over 2 years. It was an easier course, but it wasn't because of the new clubs, but the 3 lessons and range practice I had to that point. I'm pretty sure the clubs helped a bit, being more forgiving and the fact that shiny things make me happy, but the lessons were the best investment I've made in the sport.
In summary, you should get a fitting just to be sure. I think if your height and other measurements aren't average, fitting a club will promote better posture and overal swing as you get better. In terms of shaft flex, which is a hot topic everyone likes to argue about, use your judgment and feel for what is better for you. Don't let ego / machismo get in the way thinking that you have to swing fast all the time. At the course, my swings are easier and I'm hitting my 7 iron straight and anywhere between 150-160. According to many charts, stiff flex is still recommended for that kind of distance.
Here is a good video to watch on shaft flex: http://youtu.be/MDaKUHxk0I8 watch his tempo, it's smooth and consistent. If your tempo is fast and jerky, more torque is introduced, and shaft flex become very important.
Tomorrow I'm getting a new driver fitted. Currently hitting an old Ping G5 R-flex and I'm hooking it a lot. Went to the golf shop a few days ago before closing and the fitter said I need to go stiff with an average swing speed of 97mph. I'm going to trust him because I know it's hard for me to make square contact with the ball. I was hitting a couple stiff shaft drivers and I can already tell the difference from trackman's data. With a driver, which is the longest club in your bag, getting it properly fitted for shaft flex is more important imo.