My wife and I had the unfortunate experience of staying here 29/4 and 30/4.
The hotel itself is fine- good clean rooms and decent price etc BUT the whole hotel was filled and we really do mean filled with families with sub-school aged children. Some well behaved but an awful lot not. Whatever if your thing is to spend a weekend surrounded by noisy children running amok occupying every available seat then this is certainly for you.
Apparently a new kiddies theme park was opened nearby at the beginning of April, so maybe for anyone wanting a peaceful break it might be best to avoid all weekends and school holidays.

I booked a stay and cruise package here for 35 nights and agreed a price of £3.50 a night.Unfortunately my cruise was cut short due to a family bereavment .I was astonished to find that they refused to refund the unused weeks of prepaid parking. I complained as high as the Group Legal Chief who just lied and misrepresented every aspect of the contract.Every time I presented evidence of what they agreed to supply they twisted it round.
Customer Service of this Company is appalling which is a shame because the Hotel itself was clean and comfortable.

I stayed here recently for a business conference and despite being 'at work' I managed to relax and enjoy my time at this hotel.
This place is ideal for business people, the rooms have high speed wi-fi and a work desk and there are five air conditioned conference rooms
with complimentary tea and coffee facilities.
The Great Room restaurant has a good selection of food at reasonable prices and the staff are very professional and friendly.
I'm not a cricket fan but if you are, one of the benefits of staying at this hotel is that it's directly adjacent to the Rose Bowl. I beleive it's near Marwell Zoo and Paultons Park as well.
There's no lap of luxury here but the Holiday Inn Southampton is affordable, clean and well run - good enough I would say for even the most discerning visitor.