houses on the rise

Same with phi felt and phi psi.

Taus may blow now but I have still never seen, heard of, or met a SigNu in the years I've gone here

Sigma Nu is a relic of the past. For many decades they were the king of small houses < 50 members. They came from wealthy families, were largely on the golf & swimming teams and blocked with top tier sororities. A plethora of bad behavior caused them to lose their charter for like 5 years. They do have a very strong alumni network who ensured their house was kept. Their philosophy is now, more or less, to maintain strong brotherhood by staying small, excel academically and stay out of trouble by staying "off the radar" through gentlemanly behavior. The jury is still out as to whether this new "model" will ever again provide Sigma Nu "top house" status in the eyes of the masses. Perhaps their members/alumni don't recognize this important anymore?

How large was Sig Nu's pledge class ?

SN was one of the better small houses, when they were divided into 2 groups (way back it was Blue for big houses, Orange for small houses). Maybe there was a brief period when they pledged rich kids, but mostly and through today it has been kids from small towns and South suburbs of Chicago, who tend to be pretty responsible and do ok for themselves. I wouldnt say being one of the best small houses is the same status-wise as being one of the best big houses, who pledge varsity athletes and guys with "III" at the end of their names.

But when it all comes down to it, everyone should pledge the fraternity where they feel most comfortable with the guys they meet. The university seems to be on the attack against fraternities and any kind of tradition, so maybe we should stick together more.

Sigma Nu is not close to ATO yet, but keep in mind that ATO initiated, what, about 25 guys this year? Things tend to change only in the long term, but change nonetheless.

please provide examples of houses that re-chartered and achieved status within only a few years

From what I understand, house status is in perpetual flux.
Many houses now considered top tier were formerly mid or even bottom tier at some point. Conversely, some middle tier houses will achieve top tier at some point. It takes a long time for a house to achieve/regain top status. However, top status can be lost in the blink of an eye. Many examples exist, currently, and in the past.

Sit down with your older alumni and ask them to explain who were kings in their day. Depending on the decade, you'll hear Sigs, ATO, Betas, Phi Delts, Pikes, Sigma Nu, Delta Chi and Acacia. It also doesn't take an engineer to figure this out as much can be surmised by studying old Illio yearbooks.

Sigs are probably the only fraternity to maintain "top 3 status" consistently over the last 100 years. Regarding sororities, Theta and Tri Delt are the long-standing queens with Delta Gamma and Alpha Chi falling in close behind.

King status tends to be fragile, illusive and short-lived while queens have more of a "stranglehold" on perpetual top tier status.

Delts & SAE were not historically top tier.