It's a 64oz model which is a touch over 5 lbs. First off that seems a little heavy. And sure enough the wing loading is up at around 10 oz/sqft. That's a little high for a simple fly around model that you want to use for relaxed flying and thermal hunting. But once you learn a little more on an 8oz/sqft setup you might find that the added weight lets you move around the sky a lot easier with a better cruise speed.
It's pretty standard that with a 100watt/lb power loading that you can pretty much go just about straight up. So with the 700 watts setup providing 130 something watts per lb we're looking at a rocket like climb. But it's not over the top for contest work if that's your goal.
If you're only looking for flying for yourself and you don't mind if the model requires a minute of run time to reach 500 feet than you can get by with down around 70 to 75 watts per lb just fine. So a 400 to 450 watt setup will do nicely.
And the slightly lighter setup will aid in keeping the wing loading down a little.
It's a nice looking design that obviously pays some homage to the Bird of Time but uses more straight lines to make building a little easier.
But if I were building this design I'd modify it to lose the pod and boom like building method in favour of extending the pod fuselage back all the way to the tail. I'd do this for two reasons. First the sudden stop of the pod creates more drag than we want on a sailplane. But more importantly a stick build boom like this is bound to break frequently if the pilot catches a wing and causes a sudden side shift or full on ground loop on landing. The weight of the tail is simply going to whip the boom and snap it far too easily in anything other than a good smooth landing. A regular tapered box fuselage that extends to the tail will greatly aid in avoiding this aspect.