One, practicing both grips at once does not work to benefit the other grip, with the exception of the right hand, which stays the same regardless. Matched Grip, or MG, works about 13-15 muscles in the arm (can't remember the exact number). Traditional Grip, or TC, works 4 in the left arm. Those muscles are similar and different to the MG muscles. Therefore, practicing both is overkill, and overworks certian muscles, such as the wrist. If you want a workout, practice in Traditional. With less muscles being used, the work effort is increased.
Two, practicing grips does NOT lead to faster playing, and certainly not 30 minutes. Technique and chop building exercises played on a daily basis leads to faster playing. Also, a trick is to not practice rudiments or technique on drums. Yes, you will have to play them on drums, so play them there. Practice them on pillows and no bounce, on table tops and insane bounce, with marching size sticks, or Wrist Builder solid metal sticks. Only through technique exercise and CORRECT APPLICATION will one benefit.
Three, why are we switching grips? There is no point. If you want to play Snare in Drum Corps or Jazz, then Traditional is what you want. If you want to play anything else including the already said, then go Matched. Traditional was only needed when drums were angled by slings. Now, we have stands, and therefore drums are now flat. Learning both is up to you personally. I know both cause I play everything, but I mostly play Traditional UNLESS There is a specific sound I wish to draw from the drum. In that case, switching grips becomes more plausible. But judging by you post, you have no notion of drawing out different sounds.
And to answer your question, Grips are a personal preference. I prefer TG, but can play MG when the situation calls for it. I'm not playing TG on Tympani, or MG on an angled drum.
hI U guys, I started playing 38 yrs ago with the TG (george stone stick control, my fav.). 10 yrs ago I started to pratised MG, took a lot of work and it is nearly an MG with "matched control". Still very fast with TG, but I like the crispness of MG and it can be a lot heavyer.MG is much better for getting around the kit,(it feels natural) but if I want a delicate, light touch just on the snare playing close to the rim I switch to TG.I can play all the rudiments just as well with MG,but not as fast as TG.But practising either will not improve the other.
As was said TG was neccesary for marching drummers when they held the drum to the "side", other wise they could cause serious injury to them selves.But now a harness has been designed , which no doubt you would have seen used by The Top Secret Drum Corps, which holds the drum in the front.Therefor TG no longer required.So decide which grip you need and master it before changing it.I do believe the over-hand grip most natural, because of the application of the wrist movement and the availabilty of maximum finger control.
Yeah, Traditional Grip is needed for Drum Corps work at this stage of the game... aside from that... there is no NEED for it. I'm not saying it's wrong or bad. I'm just saying that the reason it was invented (as stated above) no longer exists.
I still use it (albeit rarely) if i'm doing something where i have to make a bunch of changes back and forth between using the tip and butt end of the stick in a song.
Aside from that... it doesn't make sense to me.
The myth that you have to play jazz with it , or that you play jazz BETER with it is horribly wrong