I'm looking at late model V bottoms such as Fountains, sunsations, cigarettes, etc and am trying to figure out if the extra upfront money justifies the merc 700s or if I can pay a little less and just whipple Merc 525s. I'm looking to achieve speeds over 100mph fully loaded, but 120 would be better. Have to keep the wife happy with a full cabin or would just go with a cat.

Some of my initial questions include:

How do the internals compare between a whippled 525 & 700s?
How are both on reliability?
What is a good HP expectation for a conservative whipple 525 setup?
Can Bravo XR's handle the extra HP or do I need to look at NXT or NXT6 drives?
What else am I missing?

No, XR's cannot handle Whipples running behind a 42 Fountain or 38 Cig - not to mention the horror stories you hear of Whipple installs gone bad, and bad again, and again....... depending on who does them and for that matter the horror stories of Merc 700 upgrade kit installs gone bad. You will be miles ahead by just paying up from the get-go for the stock 700's with 6's or NXT's and saving the headaches.

Go Merc 700's if your thinking about building 525's.

x2

What he said.....x100

For the record...we have done at least 20 500,525 and 700 whipple upgrades with ZERO issues.
Good luck in your search.

+1 to the 700s...

All about who does the install...

Drives, Drives, Drives. The cost to upgrade to after will out weigh the cost initially, and no headache. You prob noticed that all the 700 fountains you see for sale have #6 drives. Mash the throttles and no worries.

If done correctly the 525's will make around 700 hp and live just fine. The weak link is the Bravo drives. As others have said, pay up now and miss no days on the water due to break downs....

Keep this in mind:

An original 700SCi/NXT boat was built with the associated speeds in mind--at build time.
X-dimension and bottom tuning (blueprinting) are the two most prominent things we tune at Active Thunder based on each boat's (well) predicted speeds associated with the original engine package.
The center of gravity is also different based on the 700SCi/NXT package vs. 525/XR package. Builders may make adjustments on this based on configuration and predicted speeds; including moving weight around in the boat.

A 700SCi/NXT boat will have more transom lift than a Bravo boat running 700HP.
(As such, a 700SCi/NXT 37 Active Thunder feels different than a Whippled 525/XR derivative boat.)

The Fountains didn't handle worth a crap with the NXTs, so they would only build with a 700SCi/NXT trans & gimble/VI drive.

If you have the option to go with a 700SCi/NXT setup, more than likely it is the better way to go.