A little background here so it doesn't seem like I am simply bashing Alaskan. When we first went looking for a TC they were the top of my list as I consider them to be pretty much the best built TC there is. How many other brands still "routinely" have 40yo campers being bought and sold and still in use. That being said after it was all said and done the purchase cost was just too great to offset the other detractors (most of which I mention in the thread magic43 mentioned). I can elaborate in greater detail if you need me to.
The softside pop-ups are popular since they give a more weather/bug tight interior and provide much more amenities then the Alaskan does. At a price that is less as well.
The first obstacle to the Alaskan I see is the need to sleep 5. Unless you will have one of the kids sleeping with you or can get them all to bed down in the smallish dinette together the Alaskan isn't going to work. Even if all 3 of the kids can sleep on the dinette right now, their growing bodies will QUICKLY remove that as a viable option.
AFAIK there are only two pop-up TCs that can easily sleep 5, the Apex from Outffiter with the pull-out drawer, over dinette bed and the Northstar with the fold-out, dinette tent bed. During winter use that tent bed will get pretty cold though.
Since both the Outfitter-drawer and the Northstar-foldout are newer options (new this year for the NS) finding either one used won't be very likely.
Speaking of winter (since you mention year round use) the Outfitter is also the only pop-up that has a heated basement. This allows for actual 4-season use WITHOUT having to take special precautions against the plumbing freezing. The lack of an indoor shower in the Alaskan will really hit home during the cold of winter or other inclement weather. An outside shower is nice when everything is warm and calm but becomes a pain when its raining, windy, dusty, cold, etc.
With that many people (especially considering the kids) water supply will be VERY important. The Apex has a 44gal tank standard and can be optioned up to 60gal if the cassette toilet option is chosen.
The Northstar has the largest, most usable, bathroom followed closely by the Outfitter.
Besides offering neither a heated basement nor the ability to sleep 5 and also having the most cramped bathroom (due to its layout) a hallmark also costs more then a comparably equipped Outfitter. A new Alaskan (even without a bathroom) will cost more then either of those, while the Northstar will be appreciably cheaper then all of them, albeit with lesser quality of materials (but an outstanding reputation for service and support).
What truck are you planing on using to haul the TC? With 5 people I would recommend either the Outfitter Apex9.5 or the Northstar T1000, both of which need a longbed and would be happiest on a 1ton SRW. The Apex8 (shortbed) will also sleep 5 (and up to 60gal of water) but it has slightly less interior room and storage space.
Hope this helped and feel free to ask for more details on anything I mentioned or that you can think of.
2007 F350, SC, LB, 4x4, SRW, 6.0/auto