Recently in the same position.
It totally depends on the local situation.
Here in Bristol it was all about proceedability.(estate agent speak).
If you hadn’t SSTC then you wouldn’t have any offers taken seriously, at guide price or higher.
We had four offers, we want through each one, looked at their situation pro’s and cons.
We had one stand out couple who had sold theirs (SSTC) and had lost at least two houses after having offers accepted or being out-bid.
For us to buy, has been harder, lost at least three, out bid, matching bids sealed bids then coin toss, I kid you not!
Depending on the local market, bid early, bid the maximum you are comfortable to pay and chose an odd random number. Let the agent know you are a committed buyer, not a time waster.