We did the split tour and didn't regret it.
"In town tour" - Brian was our guide and was a blast. We had the airboat to ourselves and let him know that we were up for some adventure and wild riding. He was excited to hear and didn't disappoint! We bounced and turned and laughed a ton. We were able to view a few gators, but this part of our trip was meant for the ride. Brian was fishing as we trolled back through the dock area and hooked a fish and let our 16 year old son reel it in. It was quite the experience for him as they were probably 30 people watching and cheering. It was a snook "in the slot" which evidently is something big. (We are not fisherpeople). It was an experience our son will not soon forget.
On 41 tour - I'm sorry I have forgotten our guide's name for this one,but he told us that Brian taught him how to drive the airboats which my kids found funny because he was much older than Brian. This was the "gator viewing" portion. We saw several gators and were even able to get out and have pictures taken with one of the big males (hubby wasn't so sure about this). We were also able to see some raccoons that were obviously used to being fed by the guides and came very very close to us. This part of the trip was at a much slower pace which was perfect.
Boardwalk - we didn't arrive until after 1500 and didn't have time to get to this, although they did offer to honor our ticket the next day.
The combo is the way to go! Look for the coupons at the Visitor's point-they were $20 off the combo tour per person.