IMHO, the Mapex Saturn is evenly tiered with the Yamaha Live Custom and Gretsch Renown. I'd consider all three "entry-pro".
I think it all depends on how you define "pro". What does that even mean? Does it mean that if you are a professional musician (ie. someone making money with their gear) and you are playing a Yamaha Gigmaker kit that the Gigmaker is "Pro"?
Is Pro an indication of sound? Because many people would say that you can get 90% of the sound of the highest end kits for 10% the price of the high end kits.
Is it a reliability issue? I haven't had any parts failures on any of my kits going from a Tama Rockstar to a DW Collectors. No failures anywhere in 20 years.
Is it a fit and finish thing? My Catalinas look amazing. Their bearing edges weren't great, but I got that fixed and they are beautiful. Does that make them pro?
Is it the price that makes a kit "pro"? I would say something is only worth someone is willing to pay for it. I'm not willing to pay for a Yamaha PHX or a Tama Star kit. And considering how few of these kits are sold, it would make me believe that there are only a handful of "pro's" out there who play "pro" gear if price was our indicator.
As for a Mapex Saturn vs a Tour Custom, I would choose the Saturn (not the one linked above) because I know just how amazingly built they are, how amazing their finishes are, how durable and reliable their hardware is, how great their sound is, and how much of a bargain they are. I only know this because I own a set, literally took the entire thing apart, inspected everything for quality and craftsmanship (including every single little piece in every lug and mount), and rebuilt the thing. My particular kit is 99.9% flawless. It is much better built than my DW Collectors kit. I was stunned that this kit was built this well and sounded as good as it did.