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Revolving CC utilization is a very big part of FICO Scoring. Right now, your util is 8.6% and that's not too bad. YMMV based on your credit, but generally-speaking, FICO will start dinging you when you hit above 10% for overall and FICO also looks at individual CC util. It also likes to see $0 balances, so, I'm not sure how many more of your cards are carrying balances. IME, I've received that annoying red flag and have been dinged if more than half of my CCs are carrying balances.
If you bump up your balances on two of your CCs by $15k, then with the same $5k in prev. balances, your new util would be 34%. That's high, but not too bad. If I could guess a point hit, I would say 30-50 with most of the ding coming from EQ. Naturally, the points will come back once the balances come down to where they were before.
There are a couple of things to consider. One is the fee and interest rate. I get these checks all the time too. They become shredder fodder in a hurry. Most CCCs will charge a fee just to use the check and then an interest rate that is sometimes higher than your current APR. Read the details closely. You may be better off getting a loan from somewhere if looking to save money. One other thing to ponder is that your creditors are looking at your reports all the time. If you pull your full reports from the CRAs you can see all the soft inquiries (e.g. account reviews) from the past year or so. Most are OK with sudden changes, but some CCCs tend to get jittery with large increases. If you read in these forums, you'll see several examples of balances increasing with sudden AAs by a given creditor like credit limit decreases or financial reviews. Last year, my balances creeped up and Amex did a soft pull and saw those increased balances. They froze my account and did a financial review to make sure I wasn't backsliding.
