Hi Tim! Â We choose the Vanguard in preference over the Grandee for a couple reasons:
1) Space is a moderate issue - small back yard. Â The Grandee would fit but we did not want to go beyond the footprint that would fit our needs.
2) Primary use (we thought) would be two of us at a time. Â We have three kids but they range from 14 to 18. Â We figured on occasion we might all be in together but it would be rare. Â (Trust me, with teen schedules it is indeed rare.) Â Also, we are right on the verge of kids moving away for college so they'll be here less & less. Â

The Vanguard has no problem with all 5 of us in. Â Can you lounge, stretch out, etc? Â No, but it seems to work fine. Â We've all been in only 2 times in the six weeks we've had it. Â 80% of the time it's just 2 (my wife & I or one of the kids & I.) Â With 2 people the tub feels spacious. Â Same with 3 (that happens 1 - 2x per week.)
With the age of your kids, I'd guess you'll have a bigger crew a lot more often; and you have quite a few more years with everyone at home. Â You should set up a wet test with you HS dealer for both tubs and take the whole crew. Â Spend quite a bit of time in each tub and see if the VG feels too cramped. Â This is about the third thread I've seen the "why would anyone buy a VG when. . .) Â We absolutely love the Vanguard and it fits us perfectly. Â Don't let anyone else push your decision. Â Go try both and have fun. Â Hey, they are excellent tubs and you will be so pleased when it is right out your back door!