I think you need to figure out what you want for the applications use. I researched and installed the same build from Marty and am quite pleased with the outcome. Of course I was looking to make power in the 1500-4000 rpm range and got it plus a better upper end to 5500. For daily driving and towing #4000 with #800 in the bed, I find it a very nice balance of cost for result. Quite frankly he was the only game that didn't rely on high rpm or cost a bunch in extras to make to combo work properly.
I did the keg work myself for $100 in tools and purchasing a manifold and 12-14 hours in bench time. Bought the VRP's since $35 is pretty fair when you figure in the costs to fabricate them. I will point out Marty said the M-1 is superior over 4000 RPM,which is true. However the modded kegger hands the M1 its behind from off idle to 4000 RPM, That's to be expected as its a physics/ power band tuning issue . Shortening the runners bumps the range up, so take the M-1 claims in context. If you want low end power the modded kegger is the answer. If you need to spin it to 4000 plus, then the M1 is the way to go.
The cam is smaller than some,( roughly 450 lift and 220 duration) but with its intended rpm range and use- it does a very good job - particularly with the stock heads flow limits. The other parts are just good crafting. Long tube Headers, 3" exhaust, splash pan, oil separator, thinner head gasket for 9.3:1 ratio, all no brainers and cheap to do. I did add RHS/ INDY X heads, un-ported but with the big valves. At 244,000 miles the stock heads were ready for a refresh and it just didn't make sense for the $$ to invest in the notoriously weak stock heads,(Plus I got a killer deal on them). Take a look at a set of R/T or W-2 heads and it will be obvious how ham-stringed the factory units are for normally aspirated high rpm performance. A set of CH318s prepped by a reputable shop are also a good bang for the buck. I mention this because the heads will make the cam seem a little bigger vs what you will see with stock heads and valve sizes..But I digress.
The end result is an engine that looks stock with the exception of the headers, and performs much nicer all around and easy to live with. The only draw back was the mileage I'm getting. I used to be able to squeak 17.5 to 18 mpg with it on the highway. That's down to about 16 now. Remember this a 97 Skunk Stripe Truck so adjust accordingly.
Now I will say this. Marty has always taken the time to talk if I had a question and gave good support with the tunes and parts questions I have had, but that's just my actual experience with the guy.