You are hitting the Speedzone irons really far because the irons are so JACKED UP.....the 7 iron is 27.5*...that's whacked...my 7 iron is 34* and 6 iron 29.5*.
Though your current irons are also JACKED UP too....7 iron at 30".
Just because dispersion is better on the monitor....it might not translate out on the course.
Based on what you have wrote...I wouldn't buy the irons...you don't seemed convinced you need new irons to enjoy the game more...new irons won't magically lower your scores.
Cobra clubs don't hold their value well if you decide to sell.
Only you know whether you want to spend the money.