I would go for the larger 5.5m glass cabin boat.
 Glass softer ride for the ladies
 Cabin, ladies like a little privacy at times, and often like to chill out with a book.
 Larger.. children grow, get friends and siblings.
And 5.5  cabin is good for 3 adults.
 Once start getting out regularly, you will fine you will want to go further a feild.. the larger boat gives more options.
 And think to the future, eventually family gets bigger in more ways than one, young teenage yrs and a 6m becomes more practical.

They seem to regularly come up for sale secondhand so was wondering how they handle or if there are any known issues.

 They come up regularly cause they are a popular boat , like others , for good reason. Issues, the bolts that hold the pod on can leak.. a maintenance check thing, not major to seal and fix.
 How handle?...  hulls handle well when well powered, min or under powered they dont.
A general rule of thumb.. 5m 90 hp min  115 well powered, 5.5m 115hp min 140 well powered.
 Other alternatives.. sea nymph, haines, rayglass, tristum, bonito (thu I dont like the close windscreen).
Its very much a preference of layout.
Get ALL the the family , and/or 3 or 4 adults in the boat, move around as if in the boat...
 Then do the same on sea trial ....and talk to families at the ramp.. including, most important... the ladies.
 

I had a 485 with a 90hp Yamaha 2s. Great big little boat. Lots of cabin room - can sleep two overnight if you want to. Big front hatch makes anchoring/sea anchor access easy. You cant really walk around the side as the cabin goes right out to the edge (no walkway) so all access to the front is through the hatch.

I had a 485 was a awesome boat took it out in all conditions i loved it would still own it today if didn't need to buy a house