I have since use my Mantis for dethatching. I LOVE IT!!! It pull so much stuff out of the lawn it fill up a 40 gallon can and more....stuffed. The lawn looked nice right away, not like what other people warn me that it will look bad for 2 weeks. It does not beat up the lawn at all. It immediately look better right after. I end up re-dethatch few weeks later again and the grass looks very good now. Mantis as tiller....not so nice!!!! Jump to much, really not a substitude for even a cheap front tine tiller. I still use my cheap Poulan front tine tiller. Cultivator is a joke. It jump a lot more with the tine reverse for cultivation. I know it will work better if pulling backward. BUT, cultivating usually done around plants which is in tight space, where do you find space to pull backward. I tried for 2 minutes, it throw dirt all over the place, made a big mess, I quit end up using my hand roll cultivator instead. If you think of buying it as a cultivator around flower beds, think again!!! Get it from Mantis direct so you can return within one year free shipping. I am surprised very few people use it for dethatching. It work so well, no jumping, I can't imagine the Blue Bird can do much better, just wider so you dethatch a wider path. The tine look to be high quality that can stand up to use even commercially.

It is very unlikely that you have a thatch problem this soon after a new lawn intallation. If you can post some pictures you may get an answer that may save you a lot of time and money. BTW a machine that dethatches is called a power rake--same thing. The process of making holes in the lawn is aeration and the machine is called an aerator. Plug aeration is the most recommended type.

While bermuda can be beautiful, it is a hassle to keep it looking nice. It is one of the few grasses that should be mowed at the mower's lowest setting. Partially due to that, it should be mowed twice a week during the summer to keep from scalping it every week. Bermuda also needs as much water as all the other lawns if you want it to be green. The idea that it needs less water depends on your tolerance for brown grass. When bermuda gets very dry it becomes dormant and turns brown. When St Augustine dries out completely, it dies. Thus you have to water St Aug to keep it alive but you could stop watering bermuda altogether and it would remain alive but brown. Bermuda also needs monthly doses of high nitrogen fertilizer to stay green. This is to say that you can have a bermuda lawn but if you are not willing to maintain it, it is going to look raggedy. It can also thin out and become a haven for weeds. Back in the 50s, before the modern herbicides became inexpensive, when you bought grass seed you got a mixture of a fescue, Kentucky bluegrass, rye, and even clover. The idea was that one of the grasses would dominate in almost any soil and you could have a green lawn with multiple species of plants. That approach is one you might consider. You are in the transition zone meaning that you would be able to grow almost any grass.

Craziness or not, these substances are banned in certain parts of Canada due to the perceived risks towards children. Not looking to debate the correctness of the ban, but it is in place in certain parts of Canada, and has been for a number of years. It sounds like the OP is in Canada (Ontario) as he/she mentioned the ban. (There is even a hotline to report if you see or smell a neighbour using the banned substances!) So yes, the products are banned in the province of Ontario, Canada (and I believe a number of other provinces have a similar ban). We do have access to Roundup, but it is limited access. Bottles under lock-and-key are expensive, diluted and do not spread very far. I haven't seen the concentrated version for years so I don't think it is available to homeowners. I think that they are trying to prevent us from spraying an entire lawn, so give us limited access to the product for such things as poison ivy control. It might be difficult to buy many, many bottles (though one could go store to store to load up on lots of bottles). There was a suggestion that a professional company may be allowed to use the chemicals on the OP's lawn even though the OP could not. I think that even the professionals have to adhere to the provincial guidelines for residential lawns - otherwise - the ban wouldn't really be effective and everyone could use 2,4-D just by calling a professional. For sure, it has been years since I've smelled 2,4-D in the neighbourhood, and the professionals post signs of the chemicals they use on homeowner's properties, and I don't see 2,4-D in the list anymore. But the OP can always try - maybe they make exceptions in extreme cases. However, if you install a brand new lawn and your neighbour has a lawn full of weeds, you are pretty much out of luck as the weeds move across into your lawn quite readily. My suggestion to the OP would to ask an Ontario professional for advice as the rules are specific to our province. Perhaps the OP could simply spot treat the individual weeds in the lawn with the diluted Roundup, and then use a sod-lifter to remove the existing lawn. Then replace with new lawn. One thing for sure in Ontario is that once you install a new lawn, keep it as healthy and well-watered as possible to try to reduce the chance of it turning completely to weed again.