The TaylorMade P750 Tour Proto irons are a slightly smaller version of the P770 irons that are also a forged blade in a cavity back design to add a little bit of forgiveness.
Given that the number before the zero in the name refers to the blade length in mm then I can tell you with confidence that the P750 are 2mm shorter than the P770 and 4mm less than the P790.
Aside from that the looks are almost the same with a matt finish to the forged 1025 Carbon Steel heads that feature a shallower cavity with the same graphic lines.
The polished chrome bar across the top of the muscle back is there too and reflects the number which is a cool feature.
At address the topline is pretty thin and the heads quite compact as you might expect for an iron that has been built for TaylorMade's tour players and the Tour Proto part of the name was that used on Tour from the early part of the year when Rory & co were using these style of irons in competition.
There are some concessions to technology even in tour irons, as the 3-7 irons in the P750 set feature a 5g tungsten weight in the sole of the club to centre the CG in the middle of the face and optimise the launch conditions.
Taking the P750 on GC2 with the P770, you could see that the smaller head created a lower flight with a little less distance as the small sweetspot dropped the average distance.
The club head speed with the P750 was 2mph less on average and that could be due to the heavier True Temper Dynamic Gold S300 stock shaft compared to the ligher KBS Tour FLT 120 in the P770. Get the right shaft in both and the distances will probably be a bit more similar, but it just shows how shaft weight can influence performance as much as the head.
The specs mean that the short irons are the same lofts as the P770 until the 6-iron when the larger headed iron gets a little stronger. However it should be perfectly possible to blend the two sets as there is not much in it.
On the course, the tighter leading edge and pre-ground sole goes through the turf very well and this should enable elite players to engage in all the shot shaping they want.
With the extra material from the peripheral weighting in the head, the feel from the wedge and 8 iron was not quite as luxurious as you might get from a forged blade.
As you move into the longer irons that have the tungsten in the sole, the flow was compromised a little. However as the heads got (relatively) larger the 6 and especially the 4 came into their own as the sound and feel improved. For a set that uses effectively blade length heads, the P750 is pretty forgiving.
This will help if you want to blend the P750 long irons with the P730 blades when they come along as that might be the best use of the P750 set.
The TaylorMade P750 is not the cheapest set of cavity back blades around, but they do look good, especially with the square font numbers on the sole, but whether that will be enough in a sector that also values feel and performance remains to be seen.