Re: Which convertible to get for a newborn thru...
Also add Britax convertibles (Roundabout 55, Marathon 70, Boulevard 70, Pavilion 70CS, Advocate 70CS) to the list. For small newbies you might need the infant positioning insert, which is sold separately.
The Evenflo Triumph 65 is a decent fit for average to large newborns as well.
One other thing - since you have older kids, the option of handing seats down can usually limit the number of seats you end up buying. It might be that your kids are old enough where the convertible seats you have bought in the past are expiring soon (or have already). But definitely something to keep in mind with boosters and any new seats that you end up buying in the next few years!