Hey Roger,
Even though I have not heard the new KRK G2's for myself as of yet,I strongly suspect that they are no different than the previous Rokit series(other than having a new cone size available-5" cone),due to the fact that you're still dealing with a product with an identical manufacturing budget-hence the same price range.
Other than a new attractive design(emulating the VXT series),don't expect any sonic improvements here.
Don't get me wrong,the KRK Rokit series is among the most balanced monitors you'll find in this price range,that will give you a fairly honest mix,but I have something else in mind for you to consider....
Again,I have yet to listen to these monitors as well,but my research & experience has lead me to believe that the new Samson Resolv A6's will be a much better choice for the same money & here's why(in my opinion)....
Both companies make similarly priced monitors in the entry level range,but unlike KRK,Samson is a little more reasonably priced in the entry level of monitors(for whatever reason)....however though,when it comes to the intermediate level,KRK's prices start to soar quite high and now that Samson has stepped up into the arena of the intermediate level,they are offering the most reasonably priced intermediate level monitors I've seen thus far!
More specifically,here are the most obvious differences;
Cone material: Resolv A6's carbon fiber bi-weave vs. Rokit G2's glass aramide composite
Amplifier protection: Resolv's ferro fluid coolant & external heat sink, vs. Rokit G2's ferro fluid coolant alone
Material benefit comparisons;
Glass Aramid Composite is a mixture of paper pulp & glass fibers-which when combined,offer a stiffer & stronger cone-than just paper alone.This method is by far the cheapest way to improve on just a paper cone and this is an industry standard by which numerous companies use for entry level,budget monitors.
Carbon fiber bi-weave is made out of strands of carbon fiber(without paper) & is woven together with epoxy resins,making it incredibly light & strong(much more so than a paper & glass composite).
Another thing to be aware of,is that the new Resolv line of Samson's monitors have been drastically re-designed,in terms of upgrades in components & materials & this is Samson's best monitor that they have to offer.
Of course,you really need to hear both sets of monitors for yourself,to be clear on what you'll be happy with,but they're both the same size monitors,going for exactly the same price,so it's worth looking into.
One more thing....spec sheets are not an exact science,as each comapny has a different way of measuring a monitor's performance,in various enviroments.
Also bear in mind,that specs on low frequency responses tend to be the most inaccurate,because the amount of bass that an amplifier produces and the amount of bass that actually reaches your ears,can be very different and here's why....
Cabinent design & internal damping materials are very important in that they determine how much of the bass is preserved in translation...this is called the bass roll off point...meaning that if the path of the bass signal is cut short,the bass-in all of it's entirety,will not reach your ears.
Particularly with budget monitors,companies tend to exaggerate the low end numbers,so since the Rokit G2's read as 49Hz,you may actually only hear 56Hz(for example).
Unfortunately though,Samson is also guilty of fudging the numbers,but here is where things REALLY get interesting....
...the specs with regard to the bass response on the Samson's read as 40Hz...now obviously,this is not imperically possible-however though,with a low number like that,it's stands to reason,that you will actually hear-at the very least,49Hz out of the Samson's.
Overall,my best advice to you,is to by your monitors from a retailer that has a good return policy-one that will allow you to return your purchase,simply because you're not happy with them,because the true test of monitors do not take place until you get them in your home,to demo them properly.
Monitors of course,are a very subjective product-as it all comes down to your personal wants & tastes,but the new Samson's would be my personal top pick,based on the fact that I've owned both KRK's & Samson's in the past and the new Resolv line of Samson's seem to be the best buy out there right now,for $400(USD).
I need a secondary pair of monitors for my hardware studio and these Samson's are the monitors I plan on getting next.
I hope this helped you out & good luck in your purchase.
-Thom